Ensure your strings seat properly in the nut without buzzing! Our tempered edge-cut nut files produce round-bottom slots for nuts and saddles. Each chrome-alloy steel file has twin 4" cutting edges. Among our most popular tools, these professional files help you get the job done quickly and correctly. What files do I need? Tip: Slotting Tune-o-matic style saddles Nut slotting files work great for metal saddles. Choose your file size as you would when slotting a nut: use the same gauge as the string, or a few thousandths larger. After filing to the desired depth, we suggest polishing the slot with an abrasive cord to remove file marks and burrs.