Ring of Forging
Lets you smelt 140 Iron bars without failing
Enchanted Ruby ring
Disappears on the 140th smelt
I dont know if this glitch works anymore, but you used to be able to do 139 smelts, trade the ring, then have it traded back, and it was reset back to 0, so thats another 139... But I think it goes by your account now, Im not sure, its worth a shot for curiousity.