Special Offers Timberline 630-300 Flat Bottom Carbide Tipped Counterbore 10mm D x 11/64 Drill D x 5/16 SHK for Wood Screw Size #8-9

Flat Bottom Counterbores with Slow Spiral, HighSpeed Steel (HSS) M2 Fully Ground Drill Bits. For use in handheld drill, drill press & CNC machine when used with CNC Spring Collet*.

CNC Countersink

Drilling countersinks with these bits on the CNC machine is a great way to save time and have your pieces look great every time!

With the adjustable depth drill bit you can adjust them for whatever size material you’re working with. They are best used with a drilling toolpath, utilizing the peck drill option at 0.25” per pass with a 0.125” retract height.

For best results run at 3,000 RPM with a 30 Inches Per Minute (IPM) plunge rate. No feed rate needs to be set with these as they only move up and down with the Z axis, not side to side. If your software doesn’t allow a 0 feed rate, you can enter 1 IPM in the feed rate as a placeholder.

*For 5/16″ dia. round shank use a mm Spring Collet. For 3/8″ dia. round shank use mm Spring Collet.