My understanding with regard to bend test specimens are that when Figure 4-30 Optional Test Plate for Unlimited Thickness Horizontal Position for welder qualification is used, two side bend specimens are cut. The test plate for unlimited thickness is 1”. 4.9.3.1 Root, Face, and Side Bend Specimens refer the user to Figure 4.13 for side bends. Figure 4.13 Side Bend Specimens indicate the strips are to be 3/8 wide. So, the test “coupons” will be 1” x 3/8 x 6” in accordance with the detail at the top left of Figure 4.13. I’ve been handed some coupons that are 1” x 1/4 x 6” and was told that this is the way he’s did these tests for years. The top left detail looks very clear to me, that the coupons need to be 3/8” and not 1/4”. I’ve never used anything but 3/8” wide coupon strips. Could ya’ll please confirm whether they’re 1/4” or 3/8”? I've never heard of using 1/4".
The D1.1 structural welding code/Steel lists 3/8 inch as the required thickness for side bends. The AWS D1.1 structural welding code utilize standardized tests with standard base metal thicknesses.
When job thicknesses are permitted the bend radius is a function of the base metal and the property of elongation. A good example of this is D1.2 Structural Welding Code/Aluminum. The bend diameter is listed as a function of the M number and the F number if the filler metal isn't the same as the M number.
In the case of ASME or B2.1, the bend diameter would be 4 times the coupon thickness if the base metal was low carbon steel.
Best regards - Al