Talk:List of screw drives/Archive 3

"Cam out" description unclear
From the subsection on Phillips:


 * the Phillips screw drive was purposely designed to cam out when the screw stalled, to prevent the fastener damaging the work or the head, instead damaging the driver.

That wording indicates that it is designed to damage the driver rather than the head. If that is, indeed, the intended meaning, I think it would be clearer to say:


 * the Phillips screw drive was designed to cam out when the screw stalled. The tendency to cam out was intended to reduce the chance of the fastener damaging the work (or the driver damaging the screw head) by increasing the risk of damage to the driver, instead.

If that is not the intended meaning, then it could use a rewrite. (Indeed, the subsection on Pozidriv says that using a Phillips driver "will cam out if enough torque is applied, potentially damaging the screw head". That implies that camming out is more damaging to the head than not camming out.) Perhaps the cam-out tendency was intended more to protect the work and keep the screw from shearing than it was to protect the screw head.

The next sentence is also a little unclear--having a pronoun with an ambiguous antecedent:
 * This was caused by the relative difficulty in building torque limiting into the early drivers.

It could, perhaps, be expressed as:
 * This action was desirable due to the difficulty of building torque-limiting behavior into early drivers.

Starling2001 (talk) 22:44, 8 January 2013 (UTC)

Can we get some citations on the claim that the cam out is a feature rather than a problem? In 30+ years of manufacturing, and dealing with Phillips Corp (or whatever their name is now) I've never heard cam out touted as a feature, but rather as a problem to be avoided. In fact conversations with engineers at Phillips were centered around new proprietary drive variants that were much less prone to cam-out. Cam out of Phillips, JIS, JCIS (or cross-recess) was a major reason I have moved my designs away from that entire drive type. Ken (talk) 21:09, 4 March 2013 (UTC)
 * Looking at the Phillips patent, it seems that the claim that the it was designed to cam out is bogus, and in fact the intention was quite the opposite.

the elements constituting my present form of composite invention are constructed along complementary angular lines to effect a positive wedging engagement when the screw and driver are joined together in operative relation, instead of the driver merely occupying the space defined by the recess as is the case in the aforesaid separate screw and driver inventions. Such failure of the slotted screw to retain the blade-driver especially in power driven operations, is not only dangerous to the operator, but is likewise, always injurious to the work...
 * (p 1, col 1, line 60). The patent does mention camming out, but of detritus in the screw head, leaving the screw and driver mated:

Moreover, this slightly spaced relation permits of a camming out or crowding out of any substances which might become lodged in the recess without disturbing the predetermined relation of the driver and screw.
 * I think this bit of the article should just be removed Bazzargh (talk) 15:14, 19 January 2014 (UTC)
 * has my vote. At best it is Urban Legend, at worst just wrong.... the joys of Wikipedia. Go for it unless I get to it 1st..Ken (talk) 19:35, 28 February 2014 (UTC)

I don't have an account, but I agree, a more experienced (read- experienced in any way shape or form) editor should screen the article for references to this "intentional 'throw-out/cam-out' design" and remove them. I deigned to edit the reference on "Phillips" because the cite placed there specifically contradicted the reference. Other locations where this incorrect statement is made lack these supporting contradictory (mouthful, lol) cites. as such, I'd rather not risk doing that editing myself and being accused of vandalism or something. ;) 96.35.47.2 (talk) 02:31, 17 May 2015 (UTC)

Another Type of Drive to Document?
The type of drive which is used to mount toggle bolts to a surface, and has two opposing indentations for a tool to grip.

http://electronics.stackexchange.com/questions/77195/what-is-this-kind-of-toggle-switch-bolt-called/77196

Marhar (talk) 07:43, 28 July 2013 (UTC)


 * Those are only used on nuts, not screws, although we do seem to be covering nut designs in this article as much as screws.
 * They're actually a form of the simple slotted screwhead, but with a gap in the middle. This is a common design for nuts where there has to be space for the screw shaft (or in this case the toggle switch lever) through the middle. Bike spoke nuts use them, they were common in electrical equipment (back when this was hand-assembled with brassware, until about the '80s). We should cover these, but as a sub-form of slotted heads. Andy Dingley (talk) 09:29, 28 July 2013 (UTC)


 * Sounds reasonable to cover this here. The external link given above has some very nice pictures, but I don't know if the rights can be cleared.  Reify-tech (talk) 14:22, 28 July 2013 (UTC)


 * The photo on stackexchange is mine. I'm happy to indicate clearance rights if someone can point me in the right direction.  I've also been informed that the fastener is called a "bezel nut." Marhar (talk) 00:17, 30 July 2013 (UTC)


 * The slotted screw head is often used as a budget anti tamper head in consumer household gear (toasters, steam iron, electric kettle) and can be defeated by cutting a slot in a spare flat driver. Idyllic press (talk) 11:33, 21 February 2016 (UTC)

Eight-pointed star
I was trying to remove a screw I believed to be a Torx. It was intermediate between T15 and T20. My searching led me to this article, but it didn't help. Further investigation revealed the head has 8 points. It seems (I haven't tried yet) that a Robertson #2 will work, so I'm guessing this is a double square modification of the Robertson. Could one of our clever editors add this to the list? And the curious thing is, it's on a runabout boat manufactured in New Zealand! Cheers. — Preceding unsigned comment added by 118.208.231.2 (talk) 05:20, 12 October 2013 (UTC)


 * Huh. I thought we had had coverage of these already. Now I don't see it. These are called "double-square" because they are two squares superimposed. Same concept as triple-square, which this article already covers. The idea being that it's like a square (Robertson) but can be caught at more frequent angles by the driver bit. I will add double-square. — ¾-10 17:39, 12 October 2013 (UTC)


 * Done. — ¾-10 17:54, 12 October 2013 (UTC)



Outlaw stepped hex head
There is a new design a company called outlaw is marketing. Iamscottevil (talk) 21:23, 29 October 2013 (UTC)

Use of "anchor" and "visible anchor" templates
Please be careful about wholesale removal of "anchor" templates, because they have an important function. Per Template:Anchor, they are used as targets of Wikilinks which would remain valid even if the section were renamed. I support your removal of "visible anchor" templates, because they make it more difficult for editors to navigate the raw Wikitext. But editors often specifically add the less-disruptive "anchor" template to a target article when they create a Wikilink reference from elsewhere, and this selective addition is usually a clue that it is or will be a target of a Wikilink reference. Reify-tech (talk) 15:17, 12 January 2014 (UTC)


 * Ah, thank you for pointing that out. I hadn't thought of using such otherwise-redundant anchors specifically to make section links more durable, so that they will keep working even if others later change the heading wording. I knew people use &lt;!--comments--&gt; to discourage the breaking of such links, but wow, putting an anchor there is a much better solution anyway. Thanks for explaining. — ¾-10 23:25, 12 January 2014 (UTC)

Slotted/Torx with security pin?
I'm not intimately familiar with this variant, but curious about how this paragraph, on the face of it, makes little sense:


 * "A combined slotted and Torx drive screw was used in electronics manufacturing, notably Compaq used this type to combine the benefits of Torx in manufacturing and the commonality of flat drive in field repair situations. The slot was closed on the ends to avoid the flat blade tool slipping and damaging the electronics. A security version was also used that had a pin in the Torx recess, requiring a corresponding hole in the driving tool, be it Torx or flat drive."

If the goal was to add "commonality" with the addition of the slot, what would the rationale be for adding a security pin to such a screw? Can anyone provide some references for this section? Junkyardsparkle (talk) 05:42, 1 February 2014 (UTC)
 * I've never heard of such a thing and I'm suspicious about it, for just the reason you note.
 * Compaq, in the mid-late '80s (1987?) were the first major PC manufacturer to start using small Torx for assembly. I had a service company at the time, we had to buy new screwdrivers just to work on their first luggables and then laptops. In later years, combination slot and Torx heads became common - nasty little things, soft steel and cheap, with a worse tendency to round than the usual JST cross heads. I don't recall Compaq using these particularly, mostly the Taiwanese clones.
 * You certainly could make a combination security Torx and slot head, just set the Torx lower and make the already very shallow slothead even shallower. They'd be horrible though, the pins would bend and the slots would strip, even worse than the combinations do already.
 * I'd suggest removing the "pin and combo" claim, although "pins" and "combos" separately should remain. Andy Dingley (talk) 11:21, 4 February 2014 (UTC)
 * To clarify: there never was a Torx+slot+security screw. The last part of the quoted sentence is unclear. the reference to a flat is because a very small flat driver can be made to fit a torx recess; the pin did thwart this to a degree. Perhaps the security part should be a separate paragraph to increase differentiation.


 * Some background: The security versions were not installed at the factory and were a customer-installed option for notebooks' hard drives to prevent removal/theft. In notebooks, the security screw and a tool were packed in a separate bag with instructions. the security tool was a typical allen torx driver, but with a small hole corresponding to the pin in the torx screw head. The head pin waqs maybe .5mm? in diameter (on an m2.5 screw iirc). It worked like a champ; the screw was hardened. Busting the pin was doable but took some work. Unless the customer had installed it himself, a dealer likely would never have seen it.


 * Compaq used the (non-security) combo head in most locations, I specified the changeover from torx-only to slotted-torx while in CPQ laptop design, the desktop and server folks having used the combo 1st but in a cap head style rather than notebook's button or truss head. The addition of the slot was to specifically address the removal issues that are alluded to above and even more specifically to prevent the NEED to buy torx drivers: if you were an authorized service provider, CPQ would GIVE you some torx drivers for free; this cost lotsa $$ so a way to service the unit without giving away millions of drivers was requested. Ergo, the combo head. Once the notebooks started being designed by others, the use of JIS/JCIS heads became much more prevalent as they were preferred by the Asian manufacturers. And we lost some control over the quality of the fasteners before that as we moved sourcing offshore, the drive recesses became particularly irksome. but they cost less.....and that was about when I left. Ken (talk) 18:42, 7 February 2014 (UTC)


 * Ah, thanks for the explanation and a little history. I added a mention of the pin preventing flat-blade insertion to the "Protruding obstacle or pin type" section. Junkyardsparkle (talk) 23:08, 7 February 2014 (UTC)

Wing
I'm missing winged nuts/bolts/screws in this list. other then that compliments to the people who worked on this list. Ian Splinter (talk) 12:00, 10 October 2014 (UTC)
 * You're right, a simple wingnut should be listed, similar to List of screw drives. Perhaps the lack of a clear diagram of the head was a deterrent, but a photograph of one could be used instead, similar to Thumbscrew (fastener).  Reify-tech (talk) 20:46, 10 October 2014 (UTC)

"The Reed & Prince Mfg. Company" is introduced in the Frearson without context.
In the Frearson section The Reed & Prince Mfg. Company introduced and discussed but there is no bridging information that says why it is relevant, so it appears to be a non sequitur.

Flathead screwdriver alias
Another common alias for the 'flat-head' type is standard. It is fairly common in usage; please reflect this nomenclature.
 * it may be common but is totally incorrect. Flathead is a type of screw head. Ken (talk) 19:30, 20 July 2017 (UTC)
 * The term is already mentioned in the article. Reify-tech (talk) 19:45, 20 July 2017 (UTC)

Additionally, Hex keys have also been known as Allen wrenches. 50.126.92.226 (talk) 22:23, 16 January 2015 (UTC)screwman

Robertson and Bankruptcy
I haven't found a detailed reference for the bankruptcy story and it seems odd that the law would allow someone to purchase the permission to avoid royalty payments in a bankruptcy that the original licensee didn't have. I did find several instances of the undetailed version of the story, which makes me wonder if this isn't an exaggeration of the documentable facts. It also seems odd that http://www.robertsonscrew.com/history.html doesn't mention the bankrupcy, although it does refer to the Ford negotiations.--Wcoole (talk) 00:54, 17 January 2015 (UTC)

XZN versus Spline
There must be explained the difference between XZN and Spline drives if there is any. Missing point. Bubbletruble (talk) 12:35, 3 May 2015 (UTC)


 * Look at Spline vs. Triple Square
 * Although both of them are 12-pointed stars with relatively acute angles, those for the XZN are a triple square, generated by three overlaid squares, and so the internal angle is 90º. The XZN spline is four overlaid triangles so the angle is 60º. The difference is minimal - although the tools aren't interchangeable. A triple square driver won't fit an XZN, an XZN will fit easily and sloppily into a triple square but will chew it up. In theory the torque limit to the 60º is higher, but it's more dependent on material surface hardness. Triple squares allow softer fasteners to be used. Andy Dingley (talk) 22:15, 3 May 2015 (UTC)


 * The Picture for the 12-point flange only has 10 points. How does this differ from the 3 square or 4 triangle profile?  Idyllic press (talk) 11:34, 21 February 2016 (UTC)

Phillips Cam Out
The article repeatedly criticises the Phillips design for its tendency to cam out. This is actually how they are intended to work, the original purpose being for the assembly of aluminium alloy aircraft where over-tightening screws could be disastrous. Phillips is best for any work where over-tightening of the fastener could cause damage. Stub Mandrel (talk) 15:41, 12 August 2015 (UTC)
 * Do you know of any WP:RS for this assertion? This has been the subject of a continuing unresolved controversy. There is little doubt that cam-out occurs, but whether or not this was an intentional feature of the design is unresolved. Reify-tech (talk) 16:15, 12 August 2015 (UTC)
 * Please reference the article at https://www.instructables.com/id/When-a-Phillips-is-not-a-Phillips/ and check down the page for the paragraph where cam-out is mentioned. There is a significant issue when comparing slippage and firm grip.  In some instances, one wishes to use a lot of force without slippage and may use something like a Torx.  With a strong driver, the screw is continually screwed into the material until the depth is reached or screw breakage occurs.  In other situations, one may need to drive until the driver bit slips out of the screw.  Of course, this was before there was any adjustable clutch mechanism available on assembly line drivers.  While not an issue today, cam-out was an acceptable method of stopping at a given torque in days gone by.  --KitchM (talk) 20:29, 11 March 2020 (UTC)

Robertson Characteristics
The Robertson section says The socket-headed Robertson screws are self-centering, reduce cam out, stop a power tool when set, and can be removed if painted-over or old and rusty This sounds a little bit advertisement-y, but not unreasonably so; you have to describe the thing's characteristics somehow. However, I'm at a loss to understand what "stop a power tool when set" means.

I'm also nonplussed by "can be removed if painted-over." I see no reason why a Robertson should be more or less removable if painted over than any other kind of screw. In fact, I think it might be harder, since the paint could pool in the head and be much harder to remove than from a slotted screwdriver, for instance. Furthermore, the problem with a painted-over screw is more the fact that the paint effectively glues it into place, which really has nothing to do with the shape of the driver. Can someone more knowledgeable than I (not hard!) look at this?

* Septegram * Talk * Contributions * 01:20, 7 January 2016 (UTC)


 * I think the lack of cam out is what will force the power tool clutch to slip when driven home. Any non-cam-out head will achieve the same goal and stating it twice does seem a bit like marketing speak.
 * The painting thing is likely because the opening is larger than a corresponding slot in width and paint will not bridge as easily. Also if the paint does bridge it is likely to have left an air bubble below that you can drive the paint film into.  With narrower and sharper angle slot features and less exact driver fitting clearing a paint fillet from the bottom of a slot may be much harder.  I think it will share this characteristic with a hex drive.
 * Idyllic press (talk) 11:35, 21 February 2016 (UTC)

I was wondering the exact same thing. It would be nice if it said so. I remember using these screws to build a deck, and I seem to remember they would drive home and then the driver would "stall". I assume this is as opposed to another type which might just strip the head. As for "painting over", I assume it means that the geometry just means that even with a painted head, another smaller drive will still fit adequately, while smaller slots might just turn into shallow, rounded depressions. I also couldn't help but wonder as soon as I saw the part about it "being commonly found in Canada" if this has anything to do with the square car wheels in th South Park version of Canada. Kind of a stretch, I'm sure, but still. AnnaGoFast (talk) 05:02, 23 January 2018 (UTC)

Triangular drive?
I have seen security screws that are shaped like a triangle with rounded corners. Not sure if they have a name but I had to shape my own driver as I was unable to find any for sale at the time (decade ago). Idyllic press (talk) 11:44, 21 February 2016 (UTC)


 * I see these are described in the body as a TA or TP3 but the style is missing from the image montage so I thought they had been forgotten. Idyllic press (talk) 11:50, 21 February 2016 (UTC)

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Claw Entry
I can't find any references to a claw drive. Where they mention inverse spanner drive, they may mean inhex or allen key drive?

May need to be deleted or expanded. — Preceding unsigned comment added by 203.38.70.140 (talk) 03:02, 1 December 2016 (UTC)


 * I've never heard of it, and can't find any mention of it, other than a "Bear Claw" branding of already-discussed fasteners. Unless somebody objects, I'm going to delete it. Reify-tech (talk) 18:49, 1 March 2017 (UTC)


 * I can't say I'd ever heard of it called a "claw" drive (but then, I don't recall ever knowing any name for it), but I have once or twice encountered a fastener head that could be described as an "inverse spanner" - of the snake-eyes/pig-snout variety - with pins protruding rather than holes (as if the driver & fastener shapes had swapped places). I can't remember the context, unfortunately - just that they struck me at the time as a strange, not particularly secure, and terribly breakage and/or snag-prone design. 173.239.219.7 (talk) 19:03, 3 June 2017 (UTC)

'Opsit' screw drive image
Hi, I noticed that you added an Opsit image to the List of screw drives page. From what I can find out, Opsit just means a tri-wing (or tri-point) that has an opposite thread (i.e., no difference in screw drive), so I'm not sure that it's named appropriately. But secondly, the image consists of a black background and white centre, and from all the other screw drive graphics, white denotes the higher part and black denotes the recessed part. Therefore, is the purpose of the image to show an alternate "raised" (external) form of tri-wing? As otherwise it seems redundant. C0nanPayne (talk) 23:05, 28 February 2017 (UTC)
 * The two images are not redundant, since one shows a tri-wing and the other a tri-groove drive. I don't know why the second one is color-reversed, but it is all I could find in Wikimedia Commons. Perhaps you can get somebody in Wikipedia Graphics Lab to do a simple color reversal on the image. I tried to cleanup the confused text, and added a reference which shows and describes the Opsit more clearly. You're most welcome to improve this further if you can. Reify-tech (talk) 23:30, 28 February 2017 (UTC)
 * OK, but your reference for Opsit shows it with a Tri-Wing drive. From what I understand, this: Anti-theft Tri-groove Security Bolts is tri-groove; so even if that graphic was reversed it still wouldn't be right. I can create the SVG myself, but shouldn't it look more like this: 27: Tri-Groove® Tamper Resistant — C0nanPayne (talk) 17:17, 1 March 2017 (UTC)
 * Yes, my ref says the Opsit uses a tri-wing drive, so I tried to clean up the article's description to reflect this. i'm fairly sure that the configuration in the second picture exists, though I'm not sure what it is called. If you can reverse the colors on that image, it would be an improvement. As for the tri-groove, that image is missing entirely, and adding one like you propose would definitely help readers understand the difference between it and the other two configurations.
 * I'm going to copy this discussion to [Talk: List of screw drives], so that other editors can see it and join the conversation. Reify-tech (talk) 17:34, 1 March 2017 (UTC)


 * Opsit isn't a head design, it's simply a security-by-obscurity design where a Tri-wing head is used on a left-handed screw thread. Opsit licence the Tri-wing design and credit their trademark. I don't know why they do this, Tri-wing is optimised for driving in the clockwise direction and suffers cam-out in reverse.
 * Tri-groove is a security design (i.e. its obscurity excuses its poor torque performance) and is totally different. It has the slight advantage that the same head can be used on nuts as well as screw heads. I have some as security bolts for foglamps. Andy Dingley (talk) 18:21, 1 March 2017 (UTC)

Corresponding article in German
The German Wikipedians have far outdone the editors here in completeness, with Liste der Schraubenkopfantriebe. Their article doesn't have much explanatory text, which is where the current English article is better. I mention the German article here, because they have picked up on some useful or interesting forms we have missed so far; I'm not proposing to import their entire chart without a full discussion. Their "6-Kant Kugelkopf", "IP4-1", "Tri-Circ", and "Lox Recess" look interesting, though I haven't yet encountered them in real metal. The Germans also have developed a fairly complete portfolio of diagrams, though their graphic conventions are somewhat inconsistent. I suggest maintaining our current de facto convention of black shading for (concave) recesses, and white shading for a convex head shape, with a black outline when required. What do other editors think? Reify-tech (talk) 18:07, 1 March 2017 (UTC)

Cheese Head
The round slotted type screw head in layman's terms is also known as the 'cheese head', abbreviated as 'CH HEAD' — Preceding unsigned comment added by 196.192.189.193 (talk) 07:56, 10 May 2017 (UTC)
 * "Cheese head" isn't a drive though, it's a sideways profile for the shape of the screw head, along with pan head, button head etc. Cheese head screws were originally slotted, but nowadays they can have any drive. Allen sockets are very common for cheese heads (or at least, cheese heads are common for Allens), but so are Pozidrive / JIS cruciform drives.
 * We ought to have a similar article listing these head shapes though, and for rivets too. Screw is a bare start on it. Andy Dingley (talk) 08:45, 10 May 2017 (UTC)
 * Yes, screw head shapes should be covered in a different article, rather than this one. Reify-tech (talk) 19:45, 20 July 2017 (UTC)

There are other screw heads not included here: LHSTIX, Microstix, Quastix, Outlaw Unigrip, Hex Stix and more. — Preceding unsigned comment added by 84.123.88.105 (talk) 02:00, 28 November 2017 (UTC)