StewMac Mitchell's Abrasive Cord #52 .055" (1,40mm), 150 grit

Guitar floss! After using your nut files, smooth the string notches with Mitchell Abrasive Cord. It helps keep the strings from binding in the slots, for more reliable tuning. Available in four versatile thicknesses, Mitchell Abrasive Cord also smooths the string notches in metal bridge saddles to reduce string breakage.

Tough Mitchell Abrasive Cord is coated with durable silicon carbide and aluminum oxide microgrit. It's great for smoothing the string slots in archtop guitar, banjo, mandolin, violin and resonator guitar bridges, to help eliminate string buzz.

Cleans screw threads
Deburrs metal and plastic
Smooths fine edge details in sawn pearl inlays
Smooths bridge pin hole string slots
12-foot (3.66 meter) roll

You'll find lots of other handy uses for it in your shop!