Irwin Wood Countersinks #4 x 7/64" Size:#4 x 7/64" No other cartridges are certified

No other cartridges are certified to be fitted with this mask

design provides ultimate cutting depth to bore deeper holes in single pass

Single-spur cutting edge scribes the circumference of the hole for a smoother finish

5 mm or 3/8"

Irwin Wood Countersinks #4 x 7/64" Size:#4 x 7/64" No other cartridges are certifiedTapered drill with widened flutes for drilling fast, clean pilot holes. Adjustable four cutter counterbore cuts and clears chips quicker for fast, smooth countersinking. Counterbore attaches to flats on shank with two hex screws for a secure fit, and can be adjusted for controlled pilot hole depth. 1 4" quick change shank reduces slipping in standard chucks and is compatible with all 1 4" quick change chucks, including impact drills.