Trem-Nut As strings move in a Black Tusq XL® nut during bends and tremolo action, microscopic Teflon®, more slippery than graphite, rolls the strings back into tune. Nuts are flat, except where noted. 1/8" (3.18mm) thick nuts are for Fender and similar guitars. 3/16" (4.76mm) thick nuts are for Gibson-style guitars. Trimming and slotting required unless noted.