Lukef

They also make very good cone mandrels for making bells ,candle holders,ect. Forge the threaded end to fit in a hardy hole cut the rod around three inches past the square piece .the use the taper from the round rod to the square as your mandrel. Different size rods make different sized mandrels. I use a piece of grader blade with a square hole as they hardy. For me it is way easier for me to drive the pipe straight down to bell the end of pipe on this mandrel then any other way i have tried.

Napa auto parts sells them part number Pun516

Thanks for the welcome. Long time lurker.didn,t post until i thought i had info. to share

It is a leaf spring. It is off a peterbilt with a low air leaf suspension.