Weld Hardened Threaded Rods 1

Welding threaded rods (or even bolts on the threaded part of the shaft) is never easy nor reliable: Every thread is a stress riser out of the weld zone, and every thread inside the weld zone traps contaminants and slag and dirt. If the threads are not completely melted off and consumed back into the base metal and the weld metal, they remain uncomsumed inside the weld as stress risers.

Better to grind it smooth, weld the smooth part.

Weld hardened threaded rods - simple - stupid, stupid, stupid.

We can cure illiteracy, but there ain't no cure for stupid.

Steel alloy can be hardened only if there is sufficient alloying constituents to form martensite. Some ductility can be recovered by tempering, but at a loss of strength. The heat treatment must be closely controlled. All too often, the thermal cycles involved with welding are not closely controlled and the resulting microstructure is often untempered martensite. It is a bad idea any way you look at it.

Best regards - Al

Ohio State developed a test using threaded rod because it guarantees that at least one notch will end up in the most crack susceptible portion of the HAZ. If you want to design a part to fail, starting off by welding a high strength threaded rod is a good start.