Drill America #21 x 6" High Speed Steel Aircraft Extension Drill Bit (Pack of 12), DWDA/C Series - DWDA/CX621P12

• High-speed steel tools are good for most general purpose applications, offering a combination of hardness and toughness for wear resistance
• Black oxide treatment adds lubricity and creates small pockets on the surface of the tool that act to hold coolant near the cutting edge
• Round shanks allow use with a wide variety of toolholding systems
• When run in a counterclockwise direction (right-hand cut) spiral fluted tools evacuate chips up and out of the cut to reduce clogging
• Manufactured to National Aerospace Standard 907

Drill America DWDA/C Series High-Speed Steel drill bit is manufactured to National Aerospace Standard 907. 135 split point is self-centering and reduces thrust. Ideal for drilling in mild steels where extra length for reach is required. They have a black oxide surface treatment that is abrasion resistant, reduces chip welding and improves chip flow.