The no-sharpening cutting head is equipped with two square carbide cutters. When one edge becomes dull, the cutter can be rotated to expose a fresh cutting edge, helping maintain clean and consistent trimming performance without frequent sharpening. This bundle includes 7mm, “O”, 27/64", 10mm, 3/8", 25/64", 10.5mm, 31/64", and 12.5mm pilot shafts. The expanded size range helps support different pen tube diameters and pen blank projects. Each shaft has clear size markings for quick identification, helping reduce setup mistakes when switching between sizes. The stainless steel pilot shafts can be used to remove excess glue from inside pen tubes, clean burrs, and guide the trimming process. Each shaft also features a flat locking area designed to secure the shaft to the O'SKOOL cutting head with the socket set screw. The positioning and alignment marks help users place the flat section correctly for a stable connection. For best results, secure the pen blank with a vise or suitable holding fixture when using the trimmer on a drill press. This helps keep the blank stable and improves trimming accuracy. Package includes: 1 no-sharpening carbide pen mill cutting head 9 pilot shafts: 7mm, “O”, 27/64", 10mm, 3/8", 25/64", 10.5mm, 31/64", 12.5mm