Bend Test Fixture

By swnorris (****)

Date 03-13-2006 17:47

The specified or actual base metal yield strength is for the types of test coupons you'll be bending, not the actual test jig. The bend radius of your jig and the bend radius of your test coupons increase as the yield strength of your test coupons increase. I made mine out of A36 materials and it has lasted for years.

By jwright650 (*****)

Date 03-13-2006 17:56 Edited 06-20-2006 12:16

Scott is right the radius changes depending on the ksi of the material you need to bend. I went a cheap route and built one using a bottle jack many years ago per the the dimns given in D1.1.

Here are a couple pics of it.

http://img.photobucket.com/albums/v345/jwright650/welding%20pictures/Dsc00048.jpg .

http://img.photobucket.com/albums/v345/jwright650/welding%20pictures/Dsc00047.jpg .

John Wright

By drifter57 (**)

Date 03-13-2006 18:40

I guess maybe I was not clear enough, what I was looking at was the dimensions to use to build it . Do imake the " A" dim 1.5 or2. It depends on the yield. IF I go by actual I am over the 50 so I use 2" if I go by specified I would use 1.5", I am confused. Thanks ( my test coupons are a-572 gr 50 ) my fixture will be t-1 I need to know what radius to bend the a-572 to.

By jwright650 (*****)

Date 03-13-2006 19:17

I might be wrong, but I went with ASTM A572 gr 50 being a nominal 50ksi rather than the actual, so if my welding test doesn't bust out bending at the tighter radius, I guess I have some safety margin built in? If I went by actual, I would have some A36 materials that fit into the higher bracket also. I could build another plunger and die to match either depending on the grades I need to bend.
I hope some others will chime in and correct me if I'm wrong.
John Wright

By - Date 03-13-2006 19:42

John,

If I'm working to D1.1, Figures 4.15 to 4.17 say that I can use the "specified or actual base metal yield strength". A572 Gr50 is specified as a 50ksi yield strength material. Usually the actual yield strength is somewhat higher, so if you use 3/4" radius plunger (based on Figure 4.15), I think that in effect you do have a "safety margin" (i.e. you are using a tighter radius than might be required if you based the selection of radius on the actual yield strength of the material under test).

Drifter, I think you could use either the 1.5" or the 2" diameter plunger. If you go the 2" route, it might be a good idea to file a copy of the material certs with the bend test report, just in case it is questioned later.

Mankenberg

By jwright650 (*****)

Date 03-13-2006 21:26

Thanks for the reply Kip.
John Wright

By drifter57 (**)

Date 03-13-2006 21:35

Thanks to everybody for the input.