×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Beginner Sheetmetal question
2

Beginner Sheetmetal question

Beginner Sheetmetal question

(OP)
Beginner Question:

I have a piece of sheet metal .010 thick and need to add a bend, what's a good Rule of Thumb to figure out your inside & outside radius?

Thanks!

-Art

RE: Beginner Sheetmetal question

Hi nofear

I would use an inside bend radius of two or three times the material thickness.

regards

desertfox

RE: Beginner Sheetmetal question

The inside bend radius is a function of the tool used to make it.  In general, you should use an inside bend radius at least 1.5 * material thickness.  However, what you specify may not be what is available.  Check the radii of the available tools and select from those.  You might want a .045" radius but you'll likely not find it.  The tools we used had nose radii of .030, .060, .090, etc.

- - -Dennyd, P.E.

RE: Beginner Sheetmetal question

nofear,

This topic has been covered before. Please see the thread Sheet metal design (Thread404-65458).

Best regards,

Matthew Ian Loew


Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

RE: Beginner Sheetmetal question

nofear
Aluminum or steel?

RE: Beginner Sheetmetal question

nofear,

   The optimal sheet metal bending radius depends on the thickness and the material.  Brittle materials require a larger radius.  Take at look at the following table.

http://www.engineersedge.com/sheet_metal.htm

   This information might also be in a sheet metal catalogue.  Do a Google search.

                       JHG

RE: Beginner Sheetmetal question

No no no no no.

Talk to your fabricator and find out what his bend deduction is...all tools are different (like dennyd tried to tell you)

Then remember to cut the bend deduction in half if you are dimensioning the bend line on a flat layout.

Only the guy that bends the metal can tell you what the bend deduction is.

RE: Beginner Sheetmetal question

profengmen,

   I believe that nofear asked what the inside and outside bend radii are.  The bend deductions should be left to the sheet metal fabricator.  The fabricator we work with seems to trust SolidWorks, if that is any help to anyone.

   My old Atlas Alloys catalogue has a table showing the forming characteristics for a ninety degree cold bend of aluminium sheet.  For a thickness of .065" to .128", you multiply the thickness by the following numbers to get the inside bend radius.

Alloy             Bend factor
1100-0            0
1100-H14          0
1100-H16          2
1100-H18          3
2024-0            1
2024-T3           6
2024-T4           6
2024-T6           7
5052-0            0
5052-H32          1/2
5052-H34          1
5052-H36          3
5052-H38          4
6061-0            1/2
6061-T4           2
6062-T6           3

   This table is partial, and I have _not_ checked to see if it agrees with the web link above.

   One of the morals of this is that there are certain grades of aluminium that are very good for sheet metal fabrication, and others that are not.  6061-T6 is a popular machining grade, but it cracks when the sheet metal guys try to bend it.  Sometimes it cracks afterwards, after delivery to the customer.

   The outside radius is the inside radius plus the thickness.  :)

                          JHG

RE: Beginner Sheetmetal question

Remember, Solidworks' bend deductions are only as good as the bend table on your hard drive. Be careful!

But of course, this thread is about bend radius. And drawoh hit it on the head.

RE: Beginner Sheetmetal question

The best modern way to be sure is to cut a sample of material.  Measure the exact dimensions, have forming put a few 90 degree bends and then measure all of the legs.  You can get your bend radius and k factor by doing this.  The tooling used, method used (coining vs air bend) these will all impact the amount of stretch to the material so run some tests and you will be suprised how accurate you can get it.

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources