High Drill Step Hex Shank Hole Steel Speed Drill Multiple 3Pcs Sets Bit Step Tool&Home Improvment

High speed steel step Drill Bit Set provides fast and smooth drills on steel sheets aluminum sheets wood board board etc. (the board must be smaller in thickness than the height of step drill bits). Hex shank size: 6.35MM All drill bits come in special bag for easy transport and storage. 3x step drill Specifications: 4-32 4-20 4-12 Weight: 248g Different sized shanks ensure compatibility with 4-12/4-20/4-32mm chuck sizes. Material: high speed steel4241 Before use，please mark the that you are to drill for easier drilling and improved drill bits life.