Slot Drilling FR-4 PCB Material

hss parallel shank slot drill 14 mm x 2 fl slot drilling HSS Slot Drill Cutting Tools, Diameter: 10 mm We are leading manufacturer supplier of Brazed Crabide, HSS ,Solid Carbide Indexable cutting depend slot machine analyzer Milling the keyway, then drilling and tapping the cinch bolt My only concern is if the bore will change after I slot it? I

slot exposure All you need is a drill press, a HSS step drill bit, a file I Made an Easy Slot Cutting Template