Tekken test development for Japanese railways

Japanese small-coupon weldability test (double bevel on one plate, single on the other, weld in the joint, look for cracks). Tom translates "Tekken" as "railroad" and ties the test to Japanese railway construction of the 1970s–80s.

Pretty crude tests. When I was a welding engineer at Bethlehem Steel in the mid-70s, the Japanese liked to use the Tekken test. You take a one-inch plate or a half-inch plate, and you cut one of them in cross-section like that. The other one you bevel straight across. So you do a double bevel on one and a single bevel on the other. You put a little weld right in here, and you see if it cracks. In the Tekken test there's tremendous residual stress here even though you're only using small plates. Tekken — anybody know what Tekken means in Japanese? Railroad. This was a railroad test. The Japanese were building lots of railroads, still in the 70s and 80s, for transportation, subways and things. That was the Tekken test. But there are dozens of these types of tests where you try to use a small amount of material and test the weldability of your steel, whatever strength level it is, whatever electrodes you're going to use. You do a quick test and see if you get a crack.