Right now, my concern is getting items out of frozen soil..I've seen," hit one rock hammer with another", and possibly a chisel being hit with a hammer..Shortly, I am going to hit a few OLD parking lots that have been graveled over..They were busy in the 30's to 60's..I tried a digging knife about two or three years back in one, it (the parking lot) laughed at me..Suggestions? cordially Nad