Bend tests

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I noticed a lot of guys on here during bend tests grind the cap and the root off.  Why is this ?  I have seen the cap ground off here local before, but never the root.  There have been times where the cap and the root were never ground and coupons were bent.Journeyman / Red Seal Welder (What a useless test)Miller CST 280Miller XMT 350Miller 12vs XtremeEvolution Evo 28 mag drillEvolution 380 Dry Cut saw
Reply:There are face & root bends, and then there are side bends. We sand the face & root sides of the test coupons smooth so that the entire coupon is the same thickness ( 3/8"). Plus, the smooth sanding allows you to see the defects better.We also sand all the sides and edges of our side bend coupons so that they are the same thickness throughout, and to better see the defects.Rich
Reply:Without removal of the reinforcement the elongation of the bend specimen will not be consistent and not meet the correct code requirements if there is a code involved. Best regards, Allan]aevald
Reply:Most of my testing has been X ray.  Last bend test I did was CWB T class.  6 inch pipe sch 80, 7018 root to cap.  Grind the cap passes on the coupons and leave the root untouched.  Thanks for the info guys !Journeyman / Red Seal Welder (What a useless test)Miller CST 280Miller XMT 350Miller 12vs XtremeEvolution Evo 28 mag drillEvolution 380 Dry Cut saw
Reply:When doing root of face bends, the cap is ground down to allow the bend to stress the actual weld area. If you leave a cap on and bend, you are stressing the area adjacent to the weld and not the weld itself so much. The cap acts like reinforcement. That's why the cap is removed after a visual inspection and prior to bending in a jig.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720
Reply:^ 1+.  A local CWI also conducts a visual inspection of the root, post-removal of the backing strap.  As an aside, witnessed complete removal of the backing strap via CAC-A, versus slicing out the coupons and then manually grinding off the strap.  The former method appeared to be a time intensive and messy method of strap removal.Last edited by ManoKai; 09-10-2015 at 05:49 AM.Reason: clarification"Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi
Reply:I've washed the back strip off with a oxy fuel torch on tests in the past, then ground the rest off. I've also tested in facilities that had a milling machine and they removed the backing strip with the milling machine in very short order. The milling machine was so clean all you had to do was remove a small skim of metal with the grinder (flap disc) after.JasonLincoln Idealarc 250 stick/tigThermal Dynamics Cutmaster 52Miller Bobcat 250Torchmate CNC tableThermal Arc Hefty 2Ironworkers Local 720