Talk:Bending (metalworking)

Comment
Bend Deduction formula: The bend deduction formula has tan(A/2), and as the interior angle approaches zero, A approaches 180 degrees(=pi),  tan(A/2) approaches infinity. Clearly this is not physically reasonable. The formula works well for angles near a right angle. The formula might pertain to the apex in the diagram, which would grow to infinity as the sheet metal is bent over double. Could the formula for bend deduction be R(A-2)+T(k*A-2), where A is the exterior angle in radians (=degrees*pi/180) which works for exterior angle 90 degrees and greater bends. For bend angles less than 90 degrees exterior angle, bend deduction would depend on where one measures from in the bend. Typically one will measure from the middle of the bend, in which case the bend deduction is negligable. Great article, I find the information useful. Pmayer05 (talk) 16:49, 27 November 2012 (UTC)

Comment
Although the article is rather brief, I would like to compliment the editor who added that animated image of bending! I like that! I think Wikipedia has some good animated maps and I really would like to see more of these sorts of things as they add a certain flair to this website. Best, -- Le Grand Roi des Citrouilles  Tally-ho! 18:42, 11 July 2007 (UTC)

I wish the animation would stop after a few cycles - can that be done? Wilhkar (talk) 16:39, 6 February 2010 (UTC)wilhkar

I believe it can, but it'll increase the file size, how many times do you want it to cycle? The more cycles, the bigger the file. It doesn't bother me the way it is. Dissymmetry (talk) 17:51, 8 February 2010 (UTC)

Tables of bend factors
I would like to see a table for the different K factors for aluminum and steel based on standard stock sizes. I found some useful information on this (see below). There could be different tables based on the different bending methods. That illustration shown in the section on joggling is misleading, because of the colouring of the tool and metal material, when enlarged the illustration is discernible, but it would be more clear to the novice if a side view of a joggle were shown. When viewed side on, it is in fact a double bend a little like a Z, but not as acute an angle in the double bends. 13:05, 27 November 2012‎ 101.171.170.169 (talk)

  --Noelstalker (talk) 19:47, 11 August 2009 (UTC)

This is an old request, but it has been fulfilled. Dissymmetry (talk) 22:42, 5 February 2010 (UTC)

Page Re-write
I just finished re-writing this page, sorry I do not have sources for the information as my experience is the source and where I got my original input information is lost in the sands of time.Dissymmetry (talk) 22:45, 5 February 2010 (UTC)

This needs to be better connected to the press brake article
Because the process and the equipment are so tightly linked, this article and the one on press brakes need to be better integrated so as to not cause duplication. Wilhkar (talk) 16:38, 6 February 2010 (UTC)wilhkar


 * Perhaps the press brake article should be merged into this article because a press brake is only used for bending sheets and plates, of which this article is about. Wizard191 (talk) 18:32, 6 February 2010 (UTC)


 * I think it is good to separate the machines from the process, there are still different machines than press brakes that do bending, like the folding machines. Ooh Salvagnini, drool ... This page, the Brake page and the machines certainly need to be better crosslinked. Dissymmetry (talk) 18:15, 8 February 2010 (UTC)

Material Considerations & Advantages
I do not believe these sections are giving any useful information. I have seen materials up to 2" formed on a press brake, yes I know rediculous but true. Regardless, I think they should be either expanded greatly or removed altogether.Dissymmetry (talk) 18:07, 8 February 2010 (UTC)
 * I agree with deleting these. Wilhkar (talk) 18:55, 21 February 2010 (UTC)wilhkar

Bottoming Entry
History item: 16:17, 8 February 2010 Wilhkar (talk | contribs) (14,801 bytes) (→Bottoming: Replaced description with one that can include source citation. Is line spacing off? it is in the preview but I don't know how to change it.) (undo)

I didn't care for the citation used, I found it difficult to follow, can it be merged with what we already had and cited as summary rather than direct quote? I understand the need for citations, but I think it is better to put them in our own words unless it can't be said any better than their exact quotation. I have no problem with attributing something that is 90% my own to someone else's citation as long as they are in agreement. Additionally the changes to the definitions have eliminated the simple cohesion between them that made them each easily understood in comparison to one another ... Everywhere else we are using T for thickness, I think we should stick with that. Also if I am understanding the description correctly some of it sounds more like Air Bending than Bottoming? Dissymmetry (talk) 18:24, 8 February 2010 (UTC)


 * I defer to Dissymmetry about the source--Not as authoritative as something that has been peer reviewed. it was not a direct quote, however. TMEH (extensively peer reviewed) uses "t" (lower case) for thickness, so I agree that we should stick to that. Would you prefer that I compare the paragraph before it was changed to the source used and to TMEH, or does Dissemmetry want to revise, given your better direct knowledge? Sorry if I messed up something that was pretty good to start with. Wilhkar (talk) 19:04, 21 February 2010 (UTC)wilhkar


 * The Wikipedia verifiability policy requires that a reliable source in the form of an inline citation be supplied for any material that is challenged or likely to be challenged, and for all quotations. While strict, it also allows some flexibility on the part of the editors (us) to determine when something is likely to be challenged. This means that we can choose not use citations where we feel the statements are factual and not likely to be challenged. Dissymmetry (talk) 21:38, 22 February 2010 (UTC)

A good ref to the calculations sections
Just FYI: http://www.thefabricator.com/article/bending/bend-deduction-charts Wizard191 (talk) 19:06, 24 February 2010 (UTC)

Diagram error
The diagrams associated with the Bending Allowance and Bend Deduction paragraphs show "t" (distance from the inside face to the Neutral Line) as being measured from the "outside" bend surface, vs. the "inside" bend surface as correctly defined in previous text. —Preceding unsigned comment added by 97.115.166.20 (talk) 18:38, 14 October 2010 (UTC)


 * Fixed. Wizard191 (talk) 15:26, 27 November 2010 (UTC)

This still looks wrong/confusing to me. The neutral line looks like it's closer to the outside edge, about 0.66 from the inner edge, yet the values in the table are more like 0.33 - does this mean the diagram is wrong, or maybe small "t" should be from the outside? Since I'm not knowledgeable about this subject and using this to learn from, it's not really clear which is right. Having come to this talk page and seen the comment above, I now suspect it's the diagram that's wrong. However, that's based on the anonymous input of one person with unknown expertise/knowledge in this area, so I'm still unsure as to which is correct. JayAbbott (talk) 14:19, 23 April 2015 (UTC)

I cannot understand Joggling
Description of joggle bending wasn't enough for me to visualize it. Nice photo of the tool, tho... Cgmusselman (talk) 08:22, 24 November 2010 (UTC)


 * The photo shows a piece of metal that has a joggle bend in it. Hope that helps. Wizard191 (talk) 15:14, 24 November 2010 (UTC)


 * That does help Wizard, but the photo needs to be reshot with lighting coming from a different direction. As it is, the area of interest is in shadow. I tried photoshoping it to no avail. Roesser (talk) 16:40, 24 November 2010 (UTC)
 * Tried photoshopping it again and uploaded the result. There is some improvement, I think, but it probably could be much better by reshooting. Roesser (talk) 22:18, 26 November 2010 (UTC)

Laser Forming
I consider that laser forming should be included in this section as a new technique to achieve sheet bending and I aim the authors to contribute. More info and references could be found in the following links: http://www.iaeng.org/publication/IMECS2013/IMECS2013_pp834-839.pdf http://www.liv.ac.uk/~me0u5040/forming1.html http://www.newcraftfuturevoices.com/module/view-submissions/abstract/207/ — Preceding unsigned comment added by 47.60.88.138 (talk) 22:14, 28 January 2015 (UTC)

External links modified
Hello fellow Wikipedians,

I have just modified 5 one external links on Bending (metalworking). Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://web.archive.org/web/20100820222840/http://www.tpub.com:80/content/aviationandaccessories/TM-43-0106/css/TM-43-0106_172.htm to http://www.tpub.com/content/aviationandaccessories/TM-43-0106/css/TM-43-0106_172.htm
 * Added archive http://www.webcitation.org/5nmu2Ljx7?url=http%3A%2F%2Fwww.ciri.org.nz%2Fbendworks%2Fbending.pdf to http://www.ciri.org.nz/bendworks/bending.pdf
 * Corrected formatting/usage for http://www.sheetmetalguy.com/bend-allowance.htm
 * Corrected formatting/usage for http://www.mechengcalculations.com/jmm/metw004.html
 * Corrected formatting/usage for http://www.ciri.org.nz/bendworks/bending.pdf

When you have finished reviewing my changes, please set the checked parameter below to true or failed to let others know (documentation at ).

Cheers.— InternetArchiveBot  (Report bug) 20:22, 30 October 2016 (UTC)

External links modified
Hello fellow Wikipedians,

I have just modified 5 external links on Bending (metalworking). Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:
 * Added archive https://web.archive.org/web/20110714075046/http://archive.metalformingmagazine.com/2008/08/Press_Brake_Bending.pdf to http://archive.metalformingmagazine.com/2008/08/Press_Brake_Bending.pdf
 * Corrected formatting/usage for http://www.ciri.org.nz/bendworks/bending.pdf
 * Corrected formatting/usage for http://www.sheetmetalguy.com/bend-allowance.htm
 * Corrected formatting/usage for http://www.mechengcalculations.com/jmm/metw004.html
 * Corrected formatting/usage for http://www.ciri.org.nz/bendworks/bending.pdf

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

Cheers.— InternetArchiveBot  (Report bug) 00:13, 18 July 2017 (UTC)

Why just press brake?
As with many other industrial technology articles, this article focuses far too much on one specific method, the dominant method preferred by industry today. Press brakes are but one of several metal bending tools, and many others remain in widespread use. Classical sheet metal brakes should certainly be included, both the heavy type found in machine shops and the lighter variety used by gutter and HVAC work, not to mention hand brakes that resemble a pair of broad jawed pliers (some with vice-grip handles) that are widely used for joining HVAC ductwork. Douglas W. Jones (talk) 19:54, 9 November 2017 (UTC)