Talk:Screw/Archive 3

Picture
Also, the picture of the Carriage Bolt is labeled in error; the square shank is directly below the bolthead, then there is a round, unthreaded shank, followed by the threaded section. Acey-Deucy 16:57, 28 December 2006 (UTC)

The bolt picture is valid as there are several types of bolts, each of which have several types of geometrical features present along there shank. This picture could be said to be one of the more general cases which features the commonly found features on a bolt.

The text also seems to be missing the information pertaining to the labeling 1, 2, 3, 4 A diagram of a carriage bolt. 1. Bolt head 2. Round part 3. Square part (or carriage) 4. Bolt threads —Preceding unsigned comment added by 61.90.18.43 (talk) 04:00, 15 February 2011 (UTC)

I note that all the pan head screws I have seen actually have a chamfered/rounded lower edge to the head (it makes sense since the screw is pressed rather than cut). You can just see it in the pictures here:http://www.indiamart.com/chintamani-industries/machine-screws.html, or here: http://img-asia.electrocomponents.com/catimages/R5465604-29.jpg, but for some reason it is rarely shown on diagrams. — Preceding unsigned comment added by 203.206.162.148 (talk) 12:03, 19 September 2011 (UTC)

Lost info about wood screws
All this info was lost in the merger/redirect: [click "show" at right to view]

 A wood screw is defined as a male screw made of a metal with a slotted head and sharp point. A wood screw is commonly furnished with a flat, round or oval-head.

Briefs
In the manufacturing of wood screws, normally, steel with low carbon contents is used as a metal, manufactured by steel mills in the shape of billets which are purchased by wire rod manufacturing mills. This wire rod is further drawn by wire drawing units into different sizes of wire, required by screw or fastener manufacturers. Drawn wire has a variety of other uses as well.

Process
A wood screw passes through the following processes before coming to the packing department in a wood screw manufacturing factory where three separate machines are used for heading, slotting and threading to manufacture wood screws.
 * Heading
 * Slotting
 * Threading
 * Polishing
 * Galvanization, Blackening, Coating (these processes are omitted when not required by users or sellers)

Heading
This process is called cold forging. Wire coil is put on a stand and wire is fed into a heading machine known as the Header. This wire should not be rusty. The wire is cut into a specified size by a cutting mechanism and is pushed forward towards a die hole. A punch, fixed on a moving block, punches this wire into a die made of Carbide, encased by a protective steel covering or a die of any other suitable material to make a plug. Then a second punch presses this plug to form a blank. The shape of the head is formed according to the design of the second punch. For a flat head wood screw, a flat punch is fixed. Half round or phillips head wood screws are manufactured by grooving or embossing the shape as required on second punch. When the blank is made, a pin moving in the round die, pushes the blank out. This heading machine is also known as the Double-stroke Header. Frequent lubrication is necessary to all parts of the heading machine. Before introduction of the Double-stroke Heading machines, Single-stroke Headers were used to make blanks but are obsolete now. For the working of a Single-stroke header or "former" see also bolt manufacturing process.

Slotting
Blanks made by the heading machine are transferred to the slotting machine after polishing. Polishing is a necessary process to clean oil, dust or rust from the blanks. Rust or corrosion can damage or reduce the life of the cutter used to make slots. Blanks are put in the hopper fixed on the slotting machine, and they slide down through railing towards the rotating grooved dial which moves them towards the round cutter which is fixed on rotating adjustable shaft. Regarding the cutting speed, it is constantly proportion to the rotation of the dial. The cutter is controlled by a separate motor in some other models of slotting machines. The cutter makes the slot in the centre of the blank's head. When the blanks reach down they are dropped. Continuous lubrication is needed to increase life of the cutter. The process of slotting is skipped when the slot is made on the head by second punch on the heading machine. Slotting machines perform their function at high speed reaching up to 1600 pcs per minute (theoretically). In practice, however, a much less number of pieces is manufactured than claimed by the manufacturers of machines.

Threading
Threads are made either by rolling or cutting.

Rolling
After being polished the blanks are put in the hopper fixed on the threading machine, and they slide down the railing towards dies. Two flat dies are used, one is stationary and other is moving and the rolling faces of the dies are located opposite each other. One blank at a time is pushed towards the dies with the help of a plate known as the feeding or the starter finger. When it is gripped between hardened steel dies, the moving die rotates it and threads are formed(see notes 1) and a point(see notes 2) is made as per threading dies. The moving die is fixed in a die pocket on the block which moves further ahead and the screw is dropped(see notes 3). Threading machines perform their function at a high speed. The process is called cold forming and continuous lubrication is required to keep the dies below certain temperature.
 * Notes:
 * 1. The threaded faces of these dies are pressed against the periphery of the plain cylindrical blank and re-form the surface of the blank into threads as the blank rolls on the die faces. The working faces of the dies have a thread form, which is the reverse of the thread to be manufactured. While penetrating the surface of the blank, the dies displace the material to form the root of the thread and force the displaced material radially outward to form the crests of the thread. The blank has a diameter part way between the major and minor diameter of the thread. There is no appreciable axial movement of the blank during rolling. The diameter of the finished thread is controlled by the diameter of the blank and the distance between the faces of the dies and the finish end of the stroke.
 * 2. A small material is cut-off from the point.
 * 3. On some type of work, it is necessary to employ a "Knock-off" device to prevent the finished screw etc. from being caught by a return motion of the dies. Some machines are equipped with such a device, if not, then it is a simple matter to make one and attach it to the machine.

Cutting
The other method of making threads is cut-thread. These machines are different form Thread-rolling machines. Blanks slide though rail from the hopper (different than the hopper used in thread rolling machines) and are gripped by feeding finger one by one. The feeding finger presses down and pushes the blank into spindle head and moves up to grip the next blank. The timing of this mechanism is controlled by gears and a rotating cam along with other cams. As soon as the spindle head is closed, and the head of blank is gripped, a cutting tool moves forward to cut the other side of blank to make a point. While this tool is moving back, another tool fixed on a shaft starts cutting the threads. Cutting of threads is a three to five steps process depending upon the length and the diameter of blank. When the threads are cut and the spindle is opened, the feeding finger comes down, pulls out the screw, feeds in the next blank, moves up and before it reaches its original position, a shoot ahead part takes the screw from it.

Polishing
Polishing of blanks is repeated after they are made, slotted and threaded. A hexagonal steel drum is used for blanks polishing and a hexagonal drum made of wood is used for polishing after threads are cut or formed. Wood and leather waste is jointly or separately put inside the drum along with blanks in humid weather. Wood waste alone can do the work in dry weather. When these drums rotate, wood and leather waste absorb oil and continuous rubbing cleans and polishes the surface of blanks and screws.

Galvanization, Blackening, Coating
The process of hot-dip galvanizing, blackening or coating is done only when it is required by wholesalers, retailers or is desired by users.

Changes to the screws and bolts section
I made the changes for the following reasons: The section was overly specific about what a screw and bolt were: a. some bolts don't have heads designed to be driven. b. some screws don't have heads or at least external heads (set screws). c. threaded fasteners can mate with complementary helixes formed in other ways than tapping.

I realize that the section now repeats some of the opening. This seems a bit awkward and perhaps somebody could improve on the way I did it.

Title of the article
Part of the awkwardness is the title of this article. A long time ago I changed the title of the article to Screws and bolts or Screw/bolts. Somebody came through and changed it back without giving a reason. I still think the article should be titled, Screws and bolts. Long before me, this article morphed into an article describing screws and bolts and I don't see why it's not called that. —Preceding unsigned comment added by Davefoc (talk • contribs) 17:06, 6 May 2009 (UTC)

The impetus for the changes was the change made by 205.179.219.242. I think this is what he had in mind with his parenthetical comment. --Davefoc (talk) 17:42, 6 May 2009 (UTC)


 * I agree the article title should be something like Screws and bolts or Screw/bolt. The latter avoids plurals. Looking through the archives I dont see any resolved discussion on the title so can we change it to Screw/bolt ? - Rod57 (talk) 20:54, 6 September 2012 (UTC)

Self tapping vs. self threading
I left the term, self tapping, in place. Perhaps self threading would be better though. Self tapping is generally applied to screws designed for use with sheet metal and plastic. The machinery's handbook uses the term, self threading for the general class of threaded fasteners that form their own threads as they are driven. Davefoc (talk) 17:35, 6 May 2009 (UTC)


 * when I worked in manufacturing the standards office made a similar distinction: self tapping as a hardened screw of no particular thread designed for driving into wood or soft metal (sheet metal, lead battery terminals, etc). Self Threading used a defined thread standard, and was frequently shaped like a tap - a short tapered section with a groove to form a cutting edge and then a parallel threaded section without a groove; Self Threaders were only used in metal, and of a suitable thickness to take several threads.  The first type was intended not to be removed, the latter was intended for regular removal and refitting, and could be substituted with a standard bolt of the same thread. Air powered tools were invariably used to drive self-threading screws home the first time.


 * The (separate) wikipedia entry for Self-tapping_screw seems to conflate both types.


 * It appears that in the USA the term thread cutting screw has been coined for the second type. I've never heard it in the UK or australia (http://boltproducts.thomasnet.com/Category/screws-screw-threads-thread-cutting-screws).  It seems a sensible coinage.    Brunnian (talk) 10:38, 19 July 2009 (UTC)

Recent delete of this section
I notice that somebody deleted the whole section and the delete was reverted. In some ways the delete makes sense, IMHO. Part of this section could be used as an intro at the top of this article, combined with the part that is there now in some way or just deleted. This especially makes sense if the title of the article was changed to "Screws and bolts". Other parts of this section might get their own title like the issue of left and right handedness and the issues of rolled versus cut threads. That part needs some changes anyway because it is misleading to call rolled threads a recent advance. Davefoc (talk) 21:12, 6 May 2009 (UTC)

Minor edits for clarity. Davefoc (talk) 21:18, 6 May 2009 (UTC)


 * Anyone that works in Engineering knows there is a distinct difference between a bolt and a screw. For this reason I think that this article needs to be divided in two to reflect most common usage. No equivalence between the two, a Bolt article and a Screw article. Either that or combine the two under fasteners.Numbat01 (talk) 01:13, 9 July 2010 (UTC)


 * Once you've read the extensive archives of this page (/Archive 1, /Archive 2), you'll see that there's a lot more to this. You may as well say, "Anyone with correct religion knows that the true God is [insert_favorite_God_here]." Wikipedia lists all of the prevalent views, from natural language usage among the general public, to the conflicting prescribed definitions of various engineering and standardization bodies. — ¾-10 02:08, 9 July 2010 (UTC)
 * One of the bad things about editing Wikipedia is that it severely undermines your certainty on all manner of topics that you thought you understood perfectly well...who invented radio, what nationality Tesla was, etc. etc. - very discouraging. --Wtshymanski (talk) 02:34, 9 July 2010 (UTC)
 * Meh...I don't think of it as a negative thing, instead I find it fascinating how "history" predicates towards a certain viewpoint and that when you really study a certain aspect of it its not so clear cut. I suppose I just find the other viewpoints interesting to study. Wizard191 (talk) 12:18, 9 July 2010 (UTC)

Phillips vs Cross recess
I note almost universal usage of "Phillips" within the text to descripe the more generic cross-recess drive type. Phillips is a trademarked name and as such refers to a specific manufacturer's product. While many patents have expired, the correct term is "cross-recess". Phillips, JIS, JCIS and others are sub-types of cross-recess drive.Ken (talk) 20:55, 4 March 2013 (UTC)

change to "Other distinctions" part of the "Differentiation between bolt and screw" section
The citation was removed and a hidden note was added to the source. The note, by wizard191, says that he doubts that the alternative definition for bolt and screw listed in the link exists.

I disagree a bit. Keithonearth believed that this was the distinction in the long discussions about that section. I suspect other people have arrived at a similar idea. It might be the most rational way to define the terms. I used the reference to prove that there is some support for this distinction. The section goes on to explain that the distinction is not one that is consistent with general use or formal specification. I suspect that this may be the only reference to such a distinction on the internet, but given my general sense that at least some people believe that it is correct I thought it was reasonable to discuss it in the article. As such, I thought the section was useful as it stood and didn't need to be changed. --Davefoc (talk) 13:56, 25 May 2009 (UTC)


 * What I meant was that I don't think there's an online reference for that definition, but if a source can be found else where I have no problem including the info in the article. I couldn't let the previous reference stand because it wasn't a reliable source. Unfortunately, if a source can't be found it will have to be removed per wp:v. Wizard191 (talk) 18:02, 25 May 2009 (UTC)

We had this discussion long ago. I was concerned about the use of a questionable source and you suggested that I shouldn't use it. In general, I suspect we have similar ideas about what a reliable source is and for most purposes this kind of source would certainly not qualify as reliable. However, in this case, this source provides a reliable data point that at least somebody holds this view. Some credibility to the idea that these kind of definitions of screw and bolt exist beyond the existence of the data from this web site is that Keithonearth argued strongly for a similar definition. For me the issue is whether the view is held widely enough to justify addressing it in this Wikipedia article. I don't know the answer to that. It seems like a logical view that some people are going to come to on their own and it is reasonable to address it just for that reason, but I don't have a strong feeling about this and maybe the idea is just too obscure to be worth addressing in this article. --Davefoc (talk) 20:51, 25 May 2009 (UTC)


 * I put back the citation that was objected to. This kind of citation for this kind of thing seems to be addressed in the link to reliable sources that Wizard191 provided.  I also made some minor changes to the screws are small and bolts are big addition to this section.  It is difficult if not impossible to provide formal documentation for either idea because nothing formally defines screws and bolts in this way.  But these definitions were not presented as formal definitions.  They are in the article to discuss the ways that on occasion the terms are used informally.


 * It is possible that the entire Other distinctions section should be deleted. Certainly if there is a requirement that formal documentation be found for informal usage of the terms screw and bolt that may be necessary.  But even without that perhaps this section doesn't add sufficient value to be retained.--Davefoc (talk) 15:37, 2 June 2009 (UTC)


 * I posted the source in question to the RS notice board, which is found here: Reliable sources/Noticeboard. According to the reply I've removed the reference. Wizard191 (talk) 22:34, 6 June 2009 (UTC)


 * With respect, I think you have not understood my point. The other distinctions part of this section deals with ideas about the distinction that are not formally excepted distinctions but do have some usage.  Formal sources are not likely to be available for usage which might be common but which is not formally supported.  If this kind of source is not acceptable to document an informal usage then consideration should be given to removing the entire other distinctions part of this section since it will likely not be possible to provide any citations for it.  Also with respect, when you posted the issue about reliable sources you failed to present anything representative of what I had to say about the issue.  Perhaps most importantly, that I realized for most purposes the use of this kind of source was clearly unacceptable but that in the very limited case of what it was being used for here it might be acceptable.  In the article that you linked to this kind of use for this kind of source seemed to be acceptable for exactly the kind of purpose it was used for here. Davefoc (talk) 13:58, 7 June 2009 (UTC)


 * If a source can't be found for that section then it should be deleted per WP:V, which states "The threshold for inclusion in Wikipedia is verifiability, not truth". If the information cannot be verified then it cannot be included. I understand that you are just trying to show that other viewpoints exist, but these other viewpoints still have to have a solid foundation. We can't include an entry that says "a screw is any fastener longer than 1 foot and a bolt is anything shorter than 1 foot", just because someone stated it on their tripod website. I realize that the statement in question seems much more plausible, but that doesn't mean it doesn't need to meet the usual reliable sources guidelines. (P.S. In the noticeboard request I gave a link to this talk page, but wasn't going to rehash everything discussed, because there was just too much.) Wizard191 (talk) 22:37, 7 June 2009 (UTC)


 * Your points are reasonable Wizard191. Although I think this is a gray area that is not as clear cut as you do.  An article about prominent urban myths might reasonably enough link to a site that promoted the idea that Elvis Presley was alive.  This is a similar case in that the section is about an idea that is prominent enough that Keithonearth argued for it and that I suspect many people believe.  What I was never sure of was whether the view was prominent enough to justify mention, however it is a view that I suspect many people come to at some point that have thought about exactly what the two terms mean.  Having said that, I think whatever you do with regard to this will be fine.

Davefoc (talk) 05:30, 8 June 2009 (UTC)

I fear that the difference between a bolt and a screw may not be defineable. The definition of being able to receive a nut for bolt seems good, but I remember buying machine screws for work that fit the definition of bolt. Perhaps bolts are a subset of screws. Usage may be arbitrary as in motor/engine. --Weetoddid (talk) 22:49, 6 June 2009 (UTC)

I've added back the "alternative" definition and the link to the Structural Analysis Reference Library. It has every appearance of being a sensible reference work, and the superior usefulness and logic of the definition should tip the balance of any debate in favour of inclusion. There is obviously no descriptive definition for either term that will fit every fastener that has ever been called a screw or a bolt. The ambiguity of the terms is a vicious circle - people called a "machine screw" a screw because an ambiguity existed, and now the ambiguity is entrenched. The "alternative" definition most certainly is not descriptive, in the sense that it doesn't describe how everyone uses the two terms. But it serves as the most useful prescriptive definition - suggesting how the terms should (or at least could) sensibly be used. —Preceding unsigned comment added by Michael S G 82.152.203.195 (talk) 02:03, 12 May 2010 (UTC)


 * Please re-read the above, the problem is not if it makes sense, its that the source is not reliable per WP:RS. Also, please review WP:V. Wizard191 (talk) 13:30, 12 May 2010 (UTC)
 * ASME B18.2.1

The nominal thread length, for reference and calculation purposes, for bolts is as follows: If the bolt length less than or equal to 6", the nominal thread length is calculated as (Diameter X 2) + 0.25.   If the bolt length is greater than 6", the nominal thread length is calculated as (Diameter x 2) + 0.50. Note: Thread lengths specified above are the minimum required thread lengths to be supplied if a thread length is not specified.

Bolts have one smooth diameter which fits closely in the hole to prevent fatigue and are torqued to plasticity to stop vibration causing fatigue cracking, two diameters plus of thread length is for one nut and a lock nut. Anything threaded the entire or nearly the entire length is a screw, tapered or not. This means some short bolts could be called screws, but look at the thickness of the shank. A good bolt MUST have a washer to support the nut because the thread top is level with the shank, nuts would grind into the surface metal. The same applies to coach bolts (putting a washer under the head defeats the purpose of the head, and omitting the large washers means the nut just pulls into the wood) Lag bolts are a slight variant but the same principle, the (usually)screw end replaces the threaded end to both put tension in the bolt and open the lag shields to anchor them in the concrete. The not-threaded /not-screw length can of course be any length. Machine screws are just that, essentially fully threaded constant diameter fasteners, not intended to be used with nuts but threaded holes. Spaghettij (talk) 16:27, 8 April 2013 (UTC)

205.243.112.50 's edit to bolt/screw distinction section
205.243.112.50 changed the opening section so as to directly quote ASME B18.12 as to what the difference between a screw and a bolt is. The previous version quoted the distinction listed in the Machinery's handbook which I believe was derived from ASME B18.12. That seems to be an improvement in that a primary instead of a secondary source is quoted.

However I reverted his change overall, because:
 * 1) The wording might be improved
 * 2) It includes the comment that "This definition is distinctly different from that of a screw".  I think this is obvious.  The difficulty is that the definitions are not mutually exclusive.  Some things can be both a screw and a bolt as per the definition.  And in common usage some things that are usually referred to as bolts are actually screws based on the ASME B18.12 distinction.
 * 3) It fails to provide a lead in to the section that follows that discusses in detail some of the issues associated with the distinction of bolts and screws.

I thought that ideas as to possible changes to the section had some merit. Perhaps the paragraph should start out with the ASME B18.12 distinction. It should then follow that up with a sentence that explains that not all fasteners can be unambiguously determined to be a bolt or a screw using the ASME B18.12 distinction.Davefoc (talk) 05:35, 13 October 2009 (UTC)


 * I agree with the reversion. By all means, I support good-faith contribution, but looking at 205.243.112.50's edit diff, my first reaction was, essentially, what Davefoc said regarding "fails to provide...". This is just one of those parts of Wikipedia where you really need to read closely everything that's currently there before attempting to improve it, because the amount of exhaustive analysis already poured into it was very large. Best to all, — ¾-10 02:48, 14 October 2009 (UTC)

Reverting this change was a mistake. The language maybe should have been cleaned up but this edit actually provided the real, verifiable, source appropriate definition of the differences between a screw and a bolt. There are standards organizations throughout the world that are composed of industry experts. ANSI is the nationially accepted standards organziation in the USA. They are the definitive authority on such things as fastener standardization. ANSI, simplistically, farms the standardization of fasteners out to ASME. ASME is the clear authority when it comes to defining the difference between bolts and screws. All relative fastener organizations (ASME B18, ASTM F16, ISO TC/2, etc...) agree on the ASME B18.12 definition. There is not a single reference in any fastener technical publication anywhere to Machinery's Handbook. It is not an authority on the subject and is frequently representative of out of date information. I am willing to clean this up if it isn't going to be changed right back to inferior references like the Machinery's Handbook. (chwillia1) — Preceding unsigned comment added by Chwillia1 (talk • contribs) 21:56, 28 November 2012 (UTC)

In general, I oppose the removal of material solely because it is "obvious" -- see WP:OBVIOUS. I also even more strongly oppose deleting references to relevant standards organizations because of writing issues such as "The wording might be improved" or "It fails to provide a lead in". Such writing issues are relatively easy to fix once the information is in the article. All too many Wikipedia articles lack good references -- which seems to indicate that a lack of references is relatively difficult to fix. --DavidCary (talk) 01:56, 21 July 2013 (UTC)

Woodscrew Size Conversion
I came here looking for a Woodscrew Size Conversion Chart, between metric and screw number sizes. Please can anyone add a chart or a link to one ? Many thanks ! Darkman101 (talk) 19:32, 7 August 2013 (UTC)

Order of Sections
I think the order of sections in this article is a bit odd. I would have expected history to be first, followed by types of screws. It seems strange to me to have "differentiation of screws and bolts" as the first section. I don't think the majority of people come to this page looking to learn about the differences between screws and bolts; I'd imagine that history of screws and screw types are the most frequently sought after sections. — Preceding unsigned comment added by Blelbach (talk • contribs) 05:34, 19 October 2013 (UTC)

Inter/national standards
I am finding this page confusing or at least not confidence-inspiring because differences between various national or international standards are not made clear. For example, wood screw gauge is a number in the US and the UK. But is it the same number? Are US inches even the same as UK inches? The page doesn't say, and it refers to gauges without saying which system they come from. Hence, my lack of confidence in the information in this page ... yes, yes, I should add this info myself. But it's not my area of competence, which is why I came here in the first place. 87.113.51.124 (talk) 10:29, 18 March 2014 (UTC)


 * I've had a quick look at some US and UK wood screw size tables. They appear to be similar but I haven't seen a clear statement that they are the same. Wood screw sizes don't seem to be precisely defined as I see visible variation in the size of (UK) wood screws of the same nominal size. US and UK inches are now both the same size as they are both defined to be 25.4 mm (see Inch). (Prior to the metric definition US and UK inches seemed to differ by 3.7 parts per million.)


 * In the Lag Screw section I've removed the rider "though this can also refer to carriage bolts (round head)" from the statement "In the United Kingdom, lag bolts/screws are known as coach screws". In UK usage a coach screw only has a tapered wood screw thread. The corresponding parallel-threaded bolt for use with a nut is known as a coach bolt or a carriage bolt. These usages are already correctly shown in the Types of screw and bolt tables. GrahamN-UK (talk) 23:32, 29 May 2014 (UTC)

Types section
What does everyone think of converting the types of screws section into a table format, like the one at wrench, so that images can be included with the descriptions? I think its a cleaner layout as well. Wizard191 (talk) 16:05, 31 December 2010 (UTC)
 * Support. I think that's an awesome idea. I may be slightly biased, but that's my two cents. — ¾-10 18:08, 31 December 2010 (UTC)
 * I'd like to incorporate my changes. Peter Horn User talk 15:44, 16 February 2011 (UTC)
 * Well I finally had time to finish this off. Some notes I'd like to bring up from doing this:
 * I removed the "stud" entry, because I don't *think* a stud is a screw, however I'm not 100% sure. That's why I'm bringing it up here. The current threaded rod article, which also covers studs, doesn't refer to the fastener as a screw, which is why I removed it. Please advise if you don't think this is the best course. Also, there's still an entry for "Double ended screw"/"dowel screw" which is really a stud, so what should we do with this?
 * I also left out "thumb screw" because I think it's a screw drive, and ought to be listed there. Opinions? Wizard191 (talk) 20:08, 8 April 2011 (UTC)


 * These tweaks sound fine to me. As Wizard apparently already knows (explaining here for anyone else who wonders), a thumb screw is one of those screws with a head easily gripped by the human fingers, such that you can drive it with your fingers—the male homologue to the female wingnut. IMHO whether one discusses it in this article or in the drive types article has to be an arbitrary coin-toss, so I'm fine either way. Same with studs. They're a threaded fastener, but if this article is implicitly only about threaded fasteners that aren't driveless, then I suppose that studs should only be mentioned here in a see-also, in-passing kind of way. Makes sense. Interestingly, the distinction is "driveless", not "headless". Many types of set screws are classed as headless (no head that sticks out past the threads), but they're not driveless, because they have drives such as slots or hex sockets. — ¾-10 16:46, 9 April 2011 (UTC)
 * P.S. Nice tables. — ¾-10 16:51, 9 April 2011 (UTC)

The definitions under Cap Screw are incorrect (albeit very minor): "A socket cap screw, also known as a socket head capscrew, socket screw, "set screw" or Allen bolt, is a type of cap screw with a cylindrical head and hexagonal drive hole."
 * a set screw, as defined further in the same table, has no head. Any screw with 'cap' in the title is by this definition headed ("with a cylindrical head") therefore a set screw by virtue of being headless cannot be a cap screw. Ken (talk) 14:31, 13 August 2014 (UTC)

What's mean of R.H.P.M.S and F.H.P.M.S?
We are choosing some screws for metal door use, and would like to find the mark's means. Thanks in advance. — Preceding unsigned comment added by 183.26.40.117 (talk) 01:06, 7 December 2013 (UTC)


 * Abbreviations: FHPMS, flat head phillips machine screw; RHPMS, round head phillips machine screw. For more info on head shapes, see Screw > Screw head shapes. For more info on screw drive types, see the list of screw drives. I will gather together some more of these abbreviations and their expansions and add them to this article or a related article sometime (maybe today?). Regards, — ¾-10 18:44, 7 December 2013 (UTC)


 * Well done Three-quarter-ten. I didn't have a clue. I don't think I've ever seen those abbreviations before. I took a look on the internet and didn't get any hits. They might be old. Round head screws aren't used in manufactured items anymore and I believe the current standard books recommend that pan head screws be used instead. Davefoc (talk) 07:58, 8 December 2013 (UTC)


 * Thanks. Yeah, abbreviations of that type are pretty obscure; there are a few that non-fastener-specialist machinists and engineers may know, which are SHCS (socket head cap screw), SHSS (socket head set screw), and BHCS (button head cap screw). But the rest are so cryptic as to be of little use outside of fastener company internal communication. When I get time I'd like to assemble a list. This would be cool because then when people google them, they might crop up at the top of the results (thanks to being in Wikipedia). — ¾-10 17:40, 8 December 2013 (UTC)


 * Thanks for explaining these obscure abbreviations. I encourage you to add them to the article, because even the mighty Google turns up little of use. Explaining them in Wikipedia will be a benefit for baffled readers worldwide.  Reify-tech (talk) 17:57, 8 December 2013 (UTC)


 * This is another wiki so wrong. What has happened is modern wanna be engineers have modified what used to be considered "standard nomenclature," not abbreviations, describing screw types. There is no such thing as a BCS, button cap screw because the drive type is not indicated. BHCS is even more wrong because the "H" is never required as what else would it be other than a descriptor for the fastener? Again, modern ignorance replace ancient standards. The paradigm of the 21st century. Indeed, there should never be an "H" meaning head used for standard fastener nomenclature. Therefore, BHCS is wrong and should be BSCS for button (head) socket cap screw, BTCS for a torx drive, BPCS for a Phillips drive and so on. Likewise, FH is wrong and never was used until the uneducated took over. Flat head Phillips is simply FP with no H. HHCS is wrong once again because the "H" for head is from the department of redundancy department and is confusing because "H" was reserved for "hex" as in "hex" head.


 * I have no idea what to do about this. Should I hack the page apart to reflect ancient well established standards or should I leave it reflecting the ignorance of the Johnny come lately don't bother to learn the standards modern way? Maybe someone could answer this question? As a matter of fact, I constantly see Wikipedia pages which are clearly devoid of standards long established and then forgotten by the modern, 21st century, pseudo engineers or others. Use of incorrect nomenclature based in modern popular belief rather then long established standards leads to confusion of fastener type and application. Loss of standards replace by ignorance and popularity never results in a good outcome. Someone please insult me with the correct modern choice. MrNT (talk) 21:55, 23 August 2014 (UTC)


 * Like other words in a language, usage of technical terms is likely to drift over time, especially in the absence of formal written standards. Can anybody find written references for these claimed technical corrections?  Reify-tech (talk) 03:58, 24 August 2014 (UTC)


 * The article doesn't claim that any of these abbreviations are recommended nomenclature as specified by any specific technical standard. They are simply abbreviations that are used in industry. Any distress about how beliefs should not trump facts needs to apply also to the beliefs asserted above; and there are some verifiable problems with them. Anyone who thinks that the screw type abbreviations discussed here were ever universally standardized (that there was any one master list in existence that all corporations followed) is simply incorrect. If someone thinks that such a universal list ever existed, but can't find any evidence of it to cite as a reference, that may prompt a diatribe about secret ancient lost knowledge, but it also falls into the category of "beliefs that people badly want to add to Wikipedia even if they have no references for them". The assertion that no one should ever use "H" to mean "head" in an abbreviation such as "SHCS" may be a dearly held belief and even a nice recommendation with a good idea behind it, but it doesn't reflect any Law of the Universe. There may be no specific technical standard that specifies such "H" as part of its nomenclature, but the "H" has been in use since before the 21st century. I know for a fact that the abbreviation of "socket head cap screw" as "SHCS" predates the 21st century (and Wikipedia), because (1) I've seen it on prints since the 1990s (let alone the fact that plenty of the prints I was looking at were 10 or 20 years old, and that everyone in the building knew what "SHCS" meant—they didn't make it up, it was coming from the outside world) and (2) I just did a search for "socket head cap screw (SHCS)" between 1900 and 1990 in Google Books and found an instance in ASTM's Annual Book of American Society for Testing and Materials Standards, Volume 15, 1987. Now, you can argue "well someone somewhere else had a better nomenclature system that excluded "H" from the abbreviations." Maybe you're right. But clearly not everyone in the world was following it. It wasn't The One And Only Ancient Bible that everyone used. As for "BHCS" for "button head cap screw", I don't know when it was coined, but the simple fact is that it is now commonly used, and you can shop for BHCSs by typing "BHCS" into MSC and McMaster-Carr search fields (try it—it redirects you to the cap screws). You can shop for button head cap screws by googling ("button head cap screw" "BHCS") and find thousands of results. This means that that abbreviation exists and is used by many people. Is it an evil neologism that should be banned? Well, anyone who wants to tilt at that windmill can do so, but there's a difference between "shouldn't exist" and "doesn't exist". Even if someone can find a reference that says that "SHCS" and "BHCS" should be avoided, we would simply add that information to this article and cite the reference—we wouldn't delete the other facts. — ¾-10 22:49, 24 August 2014 (UTC)


 * It is unfortunate that inconsistent or illogical abbreviations become de facto standards in an industry, but this sometimes happens. The existing table is helpful in decoding commonly-used abbreviations for fasteners, and even describes some of the inconsistencies in usage. If the existence of a better alternative naming system can be demonstrated, it should be described as well.  Wikipedia can't reform the terminology, but can only document what is already in use.   Reify-tech (talk) 00:13, 25 August 2014 (UTC)


 * Agreed. And oh, by the way: here's an instance of "F.H." meaning "flat head" in a magazine from 1970, and here's an instance from 1910. Uh oh, guess people back then missed the memo that such abbreviations weren't thought of until the 21st century. — ¾-10 03:09, 25 August 2014 (UTC)


 * As always on Wikipedia, popular knowledge rules over historical knowledge. The H for head was never used as I studied mechanical engineering over 40 years ago with tables showing at that time the few fastener styles and there nomenclature.  That is lost in the land of non-digital text.  With the onset of the digital age, print references literally have been thrown in the dust bin being almost completely ignored.  I suspect this is true here also.  The idea of drifting terminology flys in the face of engineering and standards for without order chaos must be the result which is exactly what is observed.  We have no rockets to fly to space because standards are lost and the ability to produce such a rocket is gone.  Lost at the same time the standard drifted into oblivion.73.185.194.135 (talk) 12:52, 26 August 2014 (UTC)


 * I share many of your concerns. However, Wikipedia can't set engineering standards or change word usages, but can only document and explain them.  If you are concerned about the loss of old knowledge, try to find it on Google Books and reference the material you find in the relevant Wikipedia articles.  If the material is not web-accessible but is old enough to be out of copyright, you yourself can scan and upload it to Wikibooks for preservation and worldwide accessibility.  "It is better to light a candle than curse the darkness."  Reify-tech (talk) 16:48, 26 August 2014 (UTC)

73.185.194.135, you're mixing some things together in your mind, some of which are true trends and some of which are scary extrapolations of those trends into frightful ghosts. To start, you're conflating (1) the total variety of what existed on earth 40 years ago versus (2) which subset of it that you saw at that time, based on the particular books and periodicals you were looking at (a subset of what existed). You say "The H for head was never used", and yet I just showed you scanned copies, scanned directly from printed books and magazines from 1910 and from 1970, of people using it. Your idea that "it didn't exist at that time" is wrong, which is verified using printed books and magazines from that time (despite your fear that all such printed works are equally lost). Please understand that I'm not picking on you, either. I am just duly defending the valid info that is collected here and pointing out the aspects of what you're crusading about that are misextrapolated. You should breathe easier knowing that the misinformation that the ignorant kids share online today is often more falsifiable than your fears suggest. The stuff that's wrong (as in counterfactual) is quite often exposed sooner or later. As for what's "wrong" as in "things people do that you wish they didn't"—rest assured that that's been going on since long before the internet. It is certain that many American machinists and hardware dealers were using 'H' for 'head' in the 20th century (which the 1910 book gives evidence of, and which I encountered personally in the 1990s). This article covers the terms that machinists and hardware dealers use just as much as it covers the recommended nomenclature of engineering societies. You've taken a legitimate general concern about how experts interact with amateurs since the advent of the Web (these damn kids mostly don't even look at printed works anymore) and extrapolated it in your mind into a bit more of a monster than it is (fortunately, there are [literally] millions of printed works at everyone's fingertips at http://books.google.com/advanced_book_search and https://books.google.com/ngrams/—people may not get engineering books out of the library much these days, but OCRd scans of millions of those books are available online for falsifying wrong ideas). Nothing in this article contradicts reality, either of today or decades past. If there's a piece of reality missing, feel free to add it. But your idea "The H for head was never used 40 years ago" isn't reality. It would have to be modified to "no standardized engineering nomenclature used 'H' for 'head' 40 years ago" in order to be a piece of reality. And you could probably point to multiple MIL standards, ASTM standards, SAE standards, and British Standards that don't use the 'H' in their nomenclature. As for the idea that "standards don't exist anymore", that's actually completely wrong—there are a shitload of standards that manufacturers currently have to comply with (ASTM, SAE, NAS/AS/AIA, the many active MIL standards, ISO, FDA, and many others). The boobs chatting on Yahoo aren't consulting them, but people in the manufacturing industries are damn sure consulting them every day, at sites like this, where they pay through the wazoo for copyright-protected PDFs of them (although a lot of sharing of copies on the down-low happens, too). Your idea (paraphrased) that "nothing that was printed back then is ever looked at now" is a misextrapolation; although that is often true, the links above are some of the instances when it is not. You may have a belief that "the best engineers didn't use the H", but that is different from "it didn't exist." Regarding "We have no rockets to fly to space because standards are lost and the ability to produce such a rocket is gone"—Although it is well publicized that a lot of institutional memory from the Saturn V era is lost thanks to people getting older and passing away, paper files being discarded or crumbling away, the damn kids and their video games, and so on, the idea that the news media drums into our heads—about some planet of the apes type of loss of technology—is something that they do on purpose to rile people up into a worried, angry froth. Much of it is clickbait, but some of the people churning it out believe it, too, because many of them have little accurate understanding of the topic. Here is a news story closer to the truth of what is happening in terms of future space tech. It's not all just a bunch of apes clambering over the half-buried Statue of Liberty. To sum up, don't let the media scare you into believing an evil-clown caricature of what really is happening. Yes, good information gets lost or siloed. But the aerospace, defense, and medical device industries are still cranking out high-tech stuff. And if the people who hold the purse strings ever decide to build a new Saturn-type rocket, you better believe that Boeing and Lockheed and their legions of suppliers will reinvent one that works, for enough billions of dollars. Of course, we'd better tend to the economic underpinning of that, though, if we want any billions to exist. So squashing the middle class (and thus cratering our economy) is not in the MIC's own interests, and hopefully they will realize it eventually. — ¾-10 23:22, 26 August 2014 (UTC)

What does shaft mean?
This article currently defines "shank" with a good reference. Great!

Unfortunately, this article currently uses "shaft" a few times without illustrating or defining the term.

I was on the verge of editing the article to say that "shaft" and "shank" are synonyms, as a result of the above "" discussion.

But then I came across one website that seems to say that (paraphrasing): The shaft is the smooth, unthreaded section from the underside of the head to the start of the threaded section. The shaft is only a small part of the shank.

Can we get reliable sources defining "shaft"? --DavidCary (talk) 00:13, 13 February 2015 (UTC)


 * What that Slideshare presentation calls the "shaft" is called the "grip" in the American fastener industry. In other words, the unthreaded portion of the shank. As an American I was not formerly aware of any Commonwealth usage in which the word "shaft" in this specific sense is synonymous with that sense of "grip", but given the South Asian origin of the slides, I wondered whether that's the operative difference. Some patient googling with various quoted terms suggests that at least some English speakers around the word call the grip the "shaft". I could not find any reliable sources to cite. Here in the U.S. one would only use "grip" for this sense. This is not something like "gasoline"/"petrol" where people would know you were using a synonym. Those with fastener knowledge would think you just didn't know the "correct" word. I should also add that the general public is not aware of this sense of "grip"—it's an industry term. — ¾-10 21:33, 13 February 2015 (UTC)


 * Why does this article use the word "shaft" when we can't find any reliable sources that use the word "shaft" to describe part of a screw or bolt?
 * Maybe we should remove all mention of the word "shaft" from this article. --DavidCary (talk) 06:17, 7 March 2015 (UTC)


 * Not all of them were appropriate to remove, but the replacement is done, to the extent appropriate. Ctrl-f found 6 instances of the string "shaft" throughout. Of those, one was meant in the sense of grip (which I replaced with "grip") and one was meant in the sense of shank (which I replaced with "shank"). The others were meant in the general sense, such as line shaft, countershaft, crankshaft, camshaft, and so on. I clarified those. I wouldn't always support a national variety change simply because (i.e., only because) it was hard to find citable sources. For technical terms, there is more lexicon that exists in industry, even some which is used daily in certain sectors and locales, than any lexicographer ever yet curated. But your point in this instance was well taken (clarify); done. — ¾-10 20:08, 7 March 2015 (UTC)

Worm screw
Is a worm screw another name for a set screw (aka a grub screw)? Should it be added? — Preceding unsigned comment added by 81.107.32.7 (talk) 07:47, 17 February 2015 (UTC)


 * Usually "worm screw" refers to the worm in a worm drive. It's a gear in the form of a screw. Regards, — ¾-10 01:18, 18 February 2015 (UTC)
 * This is correct worm screw is a type of gear, only grub screw is synonymous with set screw.


 * Sometimes a small screw used to hold a bushing on a shaft is called a "grub screw". A grub is a worm-like creature....--Wtshymanski (talk) 03:28, 8 March 2015 (UTC)


 * Very true, for sure. At the same time, though, regarding the question of "Should it be added?", I would say no, because although people may once in a while say "worm screw" when they mean "grub screw", it doesn't quite rise to the threshold of being treated as a synonym. Something about the degree of establishment as a synonym. It's almost more like a malapropism than a synonym (although the funky replacement is not by similar sound but by similar association). — ¾-10 00:07, 9 March 2015 (UTC)
 * There's also a "worm" used in 19th century gunnery, used to clear the barrel of a cannon of debris before loading - a screw-shaped device. But it's not a fastener, more of a helical hook. --Wtshymanski (talk) 00:28, 9 March 2015 (UTC)

Blacklisted Links Found on Screw
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 * http://justpaste.it/7ux
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What does shank mean?
From the opening section: Some screws have an unthreaded portion of the shaft under the head, which is known as the shank.

In every other place the word shank is use it sounds like it means shaft. For instance: Fasteners with a non-tapered shank are designed to mate with a nut or to be driven into a tapped hole.

The word shaft was replaced with the word shank throughout the article. That seemed to make sense if shank means shaft with regards to screws. Shank seems like a more specialized fastener type word. But if shank actually means the unthreaded part of the shaft then consideration might be given to modifying at least some of the sentences that use it to mean the whole shaft.

The nail article defines shank as: the body the length of the nail between the head and the point; may be smooth, or may have rings or spirals for greater holding power

It seems like shank=shaft when it comes to screws. I would like to have confirmed that with a dictionary definition but the definitions I saw didn't cover this issue, at least not unambiguously. What is the source for the definition of shank provided in the opening paragraph? --Davefoc (talk) 10:19, 18 September 2009 (UTC)


 * Hey Dave, good to see you back again. I was the one who made the change from "shaft" to "shank". The source for the text in the intro came from: . In my mind I think of the terms shaft and shank interchangeably, but I think you make a good point above. Whenever the text is referring to the body under the screw threads I think it makes sense to call that the "shaft". I would be willing to change those instances back to "shaft". Wizard191 (talk) 14:34, 18 September 2009 (UTC)


 * Hi Wizard191, from page 39 of your source:

D. Shank-the cylindrical part of a bolt that extends from the underside of the head to the point.
 * The drawing above that text ambiguously points to the unthreaded part of the bolt as the shank, but that may not mean that the entire shaft of the bolt isn't the shank. The text seems to make it clear that the entire shaft of the bolt is the shank.  This suggests to me that the opening paragraph is wrong when it states otherwise.  Davefoc (talk) 15:56, 18 September 2009 (UTC)


 * Hrm, you are quite right. I just based the text in the opening paragraph on the photo and never realized there was text that went with it. I will updated the opening paragraph to reflect this. Thanks for you diligence. Wizard191 (talk) 16:31, 18 September 2009 (UTC)


 * Good job. I think this issue is closed.

I cannot recall ever seeing 'shaft' used in this manner; 'shank' is the right term. —Preceding unsigned comment added by 72.72.20.207 (talk) 17:43, 20 January 2010 (UTC)

From ISO 1891 Fasteners -- Terminology, it is clear that shank is the unthreaded part. It is synonymous with 'body'. Other reference: https://www.boltdepot.com/fastener-information/terminology.aspx — Preceding unsigned comment added by 84.196.104.49 (talk) 14:41, 19 April 2015 (UTC)


 * Hmmm. Looks like different organizations use the word differently. A Tooling University course on fasteners uses it the way I am familiar with from industry usage (http://www.toolingu.com/class-700117-overview-of-threaded-fasteners-117.html). Thus grip + threads = shank. But it looks like various organizations use definitions such that grip (which they call either body or shank) + threads = ??? (what's their term for what we call the entire shank?). — ¾-10 22:52, 19 April 2015 (UTC)

Addition
A new editor, Glooop, made the following addition to the introduction, but not in the right place. Perhaps it can be worked into a scientific description:
 * "A screw is also an inclined plane wrapped around a cylinder."

Amandajm (talk) 06:02, 31 March 2012 (UTC)

No, its not. this more closely defines a screw thread but not a screw. — Preceding unsigned comment added by 205.243.112.221 (talk) 21:11, 28 November 2012 (UTC)


 * The view of a screw in simplest theory as an inclined plane wrapped around a cylinder is already mentioned in the lede of the "screw (simple machine)" article (which is the most appropriate place for it), but Glooop's edit was natural enough, as the limitations of the hatnote prevented that from being easily noticed. A good way to address this is to arrange the hatnotes so that screw [fastener] and screw (simple machine) can be jumped between directly. Then Screw (disambiguation) for all the rest. I just evolved the hatnotes to accomplish this. The added navigation power from the hatnote improvement will help to prevent other users from thinking that the simple machine theory is "missing" from the screw [fastener] article in future edits. Thanks, everyone, for your efforts. — ¾-10 17:15, 31 March 2012 (UTC)


 * I think your edit was an improvement, ¾-10. Awhile back, one of the editors of this article suggested that the name of the article should be something like "Screws and Bolts" which would have reduced confusion on this issue. But, despite the brilliance of the suggestion, there wasn't a consensus for the change and the title of the article remained as it is. Along the lines of your change, it seems like this sentence in the lede should be removed also: "More generally, screw may mean any helical device, such as a clamp, a micrometer, a ship's propeller or an Archimedes' screw water pump." --Davefoc (talk) 23:31, 31 March 2012 (UTC)


 * The problem was not with the information, but the placement of it, which didn't follow through from the previous sentence. I think both could be incorporated, but I'd rather it was done by someone who has a particular interest here.  My tiny brain is stressed to the max with Romanesque architecture.  Amandajm (talk) 01:55, 1 April 2012 (UTC)


 * When I noticed the sentence you added I saw it as a generalized description of screw, which I thought was outside the topic of this article. I think I misunderstood your intent now. But I'm still not quite sure of what your intent was with regard to the information you (Amandajm) added. Was it to provide information about how one might understand the operation of a screw fastener? Or perhaps it was to show how a screw fastener was a kind of screw in the general sense of the term?
 * I continue to think this sentence is outside the scope of this article: "More generally, screw may mean any helical device, such as a clamp, a micrometer, a ship's propeller or an Archimedes' screw water pump." This does sound like something that belongs in the screw(simple machine) article. --Davefoc (talk) 07:38, 1 April 2012 (UTC)


 * I do think "A screw is an inclined plane wrapped around a nail" in its present form doesn't help, and may confuse readers in this context. I cannot think of a good alternative at the moment but something like this could be a starting point:

"A screw in its most general form is one of the Simple machines of Renaissance times, and when used as a fastener the concept of an inclined plane explains how relatively little force/torque applied to a screwdriver may provide a fastening capable of withstanding high [[Stress (mechanics)|stresses]"

I also think it would be helpful to include some wording around this point to explain screws may have uniform (diameter & pitch) threads (e.g. grub screws) or have tapered threads (e.g. wood screws). Maitchy (talk) 01:01, 9 February 2016 (UTC)

History
When was the wood screw developed? The nut-and-bolt? When did they become cheap enough for common use? Paul, in Saudi (talk) 14:18, 1 November 2013 (UTC)


 * The thumbnail answer is that both are quite ancient in terms of invention. The ideas stretch so far back into antiquity that there's no compact invention storyline such as those for many more modern devices such as, say, the telegraph or phonograph. But neither became cheap and widespread until the late 18th into the early 19th century, when they both did so during the same era. Even so, they were still more expensive and less ubiquitous than the average person today would readily appreciate. (For example, even after wood screws were a viable option, carpenters often didn't feel the need to use very many; the preexisting material culture had inertia. The same was true of threaded bolts and nuts for metal fabrication. For many more decades it remained common to build a lot of things—from barns to boilers—without very many screw threads.) Throughout the rest of the 19th and the beginning of the 20th centuries, they continued to get cheaper and more widespread. The complete history is complex and interesting; it is broad enough that it is touched on in various Wikipedia articles. Screw > History gives a good overview. The top 4 links listed under Threading (manufacturing) > History round out a multifaceted view. — ¾-10 22:52, 1 November 2013 (UTC)


 * I am an Old, Old, Man. So there was a history section and I just skimmed over it? Please excuse me. Paul, in Saudi (talk) 04:21, 2 November 2013 (UTC)


 * Quite alright, I do that myself from time to time. — ¾-10 22:43, 2 November 2013 (UTC)

Actually the assertion that wood screw wer quite ancient is unsupported. The cited source states that screws as fasteners were first developed in Europe in the 15th century. The history section contains some imaginative misrepresentation of that cited source.184.45.21.70 (talk) 16:47, 25 March 2016 (UTC)

Conflict coach screw and coach bolt - Carriage bolt
This article says that coach screw and coach bolt are synonymous but different from a carriage bolt and is in conflict with Carriage bolt where a carriage or coach bolt are synonymous and are retained by a nut as opposed to a coach screw. As I suggest it should be. Cinderella157 (talk) 06:13, 31 January 2017 (UTC)


 * You are correct, article is wrong.Stub Mandrel (talk) 20:52, 25 April 2018 (UTC)