Can anyone suggest a supplier for either M1 or M2 high speed steel filler rod? A Google search surprisingly did not result in any welding supply houses that seem to carry these products. Thanks.
Try these two they should have something up 3/4" dia.
I was trying to look through my notes I don’t see in particular, but Hastalloy C is a good choice on a several tool steels. The trick is in the preheat and maintaining the interpass temperature.