My metal lathe bed is not long enough to allow drilling the hole in the end of the crankshaft. A hole needs to be drilled and tapped to retain the washer to make sure the throwout bearing and disks do not move off the end of the shaft.
I used my wood lathe with a steady rest to drill the hole and tap the 1/4-20 UNC thread in the end of the crankshaft. The chuck has sharp edges so 4 little pieces of aluminum flashing were used to shim the crankshaft and protect the finish.
The crankshaft was turned from a piece of 1.5" shafting material found at the local recycler. The throwout bearing required a 1.375 shaft so that became the standard finish size.