In this patent recreation, I work on a type of alligator wrench designed to work with tapered fasteners. Do I know of any tapered fasteners? No. Does that mean the person who originally designed this wrench in 1911 as insane? Possibly. You can view the original patent here: https://patents.google.com/patent/US9... All major parts were made of 1" thick 4140 steel hardened to 47 HRc. I tried to cut the serrated swivel-jaw portion with the metal planer, but switched to machining on the milling machine after one face because my arm was going to fall off.