Precise 4 Flute 1/4″ Straight Shank H.S.S. Aircraft Counterbore (Short Series) 13/16″ Size, 7/8″ Shank Length, 3-1/8″ O.A.L., 3/16″ Pilot Hole Dia.

• H.S.S. – High Speed Steel
• Hardness: 58 to 60 RC
• Used to enlarge the opening of a hole to allow room for the head of a screw.
• Reduced shank allows for use in electric or pneumatic drills, especially in aircraft work.
• Accepts interchangeable pilots.
• Cutting Direction: Right Hand
• Center Cutting: Yes
• Series: C10

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