This is used, as-is, with a 6-inch flat-lap faceting machine that has a 1/2" arbor. It acts as a wrench and protective accessory. Suitable for anybody.

The Arbor Knob features:
40mmx4mm recess for the large washer
19mm hex nut impression to hold the reverse thread arbor nut
13mm recessed void to accommodate any extra arbor thread protruding beyond the arbor nut
Fully modifiable to suit your personal need

Gem is made to fit and may be printed together, or two pieces. Either can be simple or very personalized for your own style. Print in another color and epoxy in place? Plate it in gold? ...it is there.

The Arbor Knob makes getting the nut to start easily and helps protect the diamond laps from damage by containing the nut...and it makes small parts bigger. Yay! The washer is not as contained, but you would be less likely to drop it, I suppose. Enjoy, share, don't sell it, and do make one for a friend.