Hello hittman375, as John told you, you will need to end up with 3/8" thick coupons before you do the bend on them, I might add just a few other items to his suggestions. I believe the code that you are testing these to will require you to make your first cut for each coupon 1" in from each end of each plate and then cut the necessary thickness of coupon from that spot. Two coupons from each plate is what you should end up with. If you are using any sort of flame cutting or heat related cutting process to prepare these coupons you will need to allow a bit of additional thickness that can be ground off to get away from having the HAZ that will result from these processes. Also, grind, polish, or sand the surfaces smooth on the coupons in such a manner that all of the grind marks run lengthwise on them. Radius the four corners of each coupon to no more than 1/8" and then bend away. You'll get the hang of doing this and your confidence will also increase over time. Good luck and regards, aevald