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    170 Products
    About Counterbores
    industrial info icon

    Create flat-bottomed holes, so your screw heads sit flush, recessed, or slightly raised.

    Changeable-Pilot Counterbores

    A popular choice when counterboring for nonstandard screw sizes, this tool creates counterbored holes for screws of various thread diameters. Attach a pilot (sold separately) that matches the diameter of your pilot hole. The pilot centers the counterbore and prevents wobbling to create an accurate recess for the screw head on the first try.
    High-Speed Steel
    Image of Product. Shown with Pilot (Sold Separately). Front orientation. Counterbores. Changeable-Pilot Counterbores.

    Shown with Pilot (Sold Separately)

    Durable and wear resistant, these counterbores make accurate cuts in most materials without chipping or cracking.
    Shank
    Uncoated
    Body
    Dia.
    Overall
    Lg.
    For Pilot
    Shank Dia.
    Dia.
    Type
    No. of
    Flutes
    Each
    3/16"3"3/32"15/64"Round300000000000000
    7/32"3"3/32"15/64"Round30000000000000
    1/4"2 3/8"3/32"1/4"Round4000000000000
    1/4"3 13/16"3/32"15/64"Round3000000000000
    9/32"2 3/8"3/32"1/4"Round4000000000000
    9/32"3 13/16"3/32"17/64"Round3000000000000
    5/16"2 3/8"3/32"1/4"Round4000000000000
    5/16"3 13/16"3/32"17/64"Round3000000000000
    11/32"2 3/8"3/32"1/4"Round4000000000000
    11/32"3 13/16"3/32"5/16"Round3000000000000
    3/8"2 3/8"3/32"1/4"Round4000000000000
    3/8"4 1/16"5/32"5/16"Round3000000000000
    13/32"2 13/16"1/8"1/4"Round4000000000000
    13/32"4 1/16"5/32"3/8"Round3000000000000
    7/16"2 13/16"1/8"1/4"Round4000000000000
    7/16"4 1/16"5/32"3/8"Round3000000000000
    15/32"2 13/16"1/8"1/4"Round4000000000000
    15/32"4 5/16"3/16"7/16"Round3000000000000
    1/2"2 13/16"1/8"1/4"Round4000000000000
    1/2"4 5/16"3/16"7/16"Round3000000000000
    17/32"2 13/16"1/8"1/4"Round4000000000000
    17/32"4 5/16"3/16"1/2"Round3000000000000
    9/16"2 13/16"1/8"1/4"Round4000000000000
    9/16"4 5/16"3/16"1/2"Round3000000000000
    19/32"2 13/16"1/8"1/4"Round4000000000000
    19/32"5 1/8"3/16"1/2"Round3000000000000
    5/8"2 13/16"1/8"1/4"Round4000000000000
    5/8"5 1/8"3/16"1/2"Round3000000000000
    21/32"3 1/8"3/16"1/4"Round4000000000000
    21/32"5 1/8"3/16"1/2"Round3000000000000
    11/16"3 1/8"3/16"1/4"Round4000000000000
    11/16"5 1/8"3/16"1/2"Round3000000000000
    23/32"3 1/8"3/16"1/4"Round4000000000000
    23/32"5 3/8"1/4"1/2"Round3000000000000
    3/4"3 1/8"3/16"1/4"Round4000000000000
    3/4"5 3/8"1/4"1/2"Round3000000000000
    25/32"3 1/8"3/16"1/4"Round4000000000000
    25/32"5 1/8"1/4"5/8"Round3000000000000
    13/16"3 1/8"3/16"1/4"Round4000000000000
    13/16"5 1/8"1/4"5/8"Round30000000000000
    7/8"3 1/8"3/16"1/4"Round4000000000000
    7/8"5 3/8"1/4"3/4"Round30000000000000
    15/16"3 1/8"3/16"1/4"Round40000000000000
    15/16"6 1/8"1/4"3/4"Round3000000000000
    1"3 1/8"3/16"1/4"Round40000000000000
    1"6 3/8"5/16"3/4"Round30000000000000
    1 1/8"6 3/8"5/16"1"Round30000000000000
     
    Carbide-Tipped Steel
    Image of Product. Shown with Pilot (Sold Separately). Front orientation. Counterbores. Changeable-Pilot Counterbores.

    Shown with Pilot (Sold Separately)

    The hardest and most wear-resistant counterbores we offer. These bits stay sharper at higher temperatures and faster speeds for the best performance on hard and abrasive materials.
    C2 Carbide—Hard enough to cut cleanly through cast iron and nonferrous metals.
    C5 Carbide—Harder than C2 Carbide, these counterbores cut steel without damaging themselves or the hole.
    Shank
    Uncoated
    Body
    Dia.
    Overall
    Lg.
    For Pilot
    Shank Dia.
    Dia.
    Type
    No. of
    Flutes
    Each
    C2 Carbide
    1/4"2 3/8"3/32"1/4"Round300000000000000
    1/4"3 13/16"3/32"15/64"Round30000000000000
    9/32"2 3/8"3/32"1/4"Round30000000000000
    9/32"3 13/16"3/32"17/64"Round300000000000000
    5/16"2 3/8"3/32"1/4"Round30000000000000
    5/16"3 13/16"3/32"19/64"Round300000000000000
    11/32"2 3/8"3/32"1/4"Round30000000000000
    11/32"3 13/16"3/32"5/16"Round300000000000000
    3/8"2 3/8"3/32"1/4"Round30000000000000
    3/8"4 1/16"5/32"5/16"Round30000000000000
    13/32"2 3/4"1/8"1/4"Round300000000000000
    13/32"4 1/16"5/32"3/8"Round300000000000000
    7/16"2 3/4"1/8"1/4"Round300000000000000
    7/16"4 1/16"5/32"3/8"Round30000000000000
    15/32"2 3/4"1/8"1/4"Round300000000000000
    15/32"4 5/16"3/16"7/16"Round300000000000000
    1/2"2 3/4"1/8"1/4"Round300000000000000
    1/2"4 5/16"3/16"7/16"Round30000000000000
    17/32"2 3/4"1/8"1/4"Round300000000000000
    17/32"4 5/16"3/16"1/2"Round300000000000000
    9/16"2 3/4"1/8"1/4"Round300000000000000
    9/16"4 5/16"3/16"1/2"Round30000000000000
    19/32"2 3/4"1/8"1/4"Round300000000000000
    19/32"5 1/8"3/16"1/2"Round300000000000000
    5/8"2 3/4"1/8"1/4"Round300000000000000
    5/8"5 1/8"3/16"1/2"Round30000000000000
    21/32"2 3/4"3/16"1/4"Round300000000000000
    21/32"5 1/8"3/16"1/2"Round300000000000000
    11/16"2 3/4"3/16"1/4"Round300000000000000
    11/16"5 1/8"3/16"1/2"Round300000000000000
    23/32"2 3/4"3/16"1/4"Round300000000000000
    23/32"5 3/8"1/4"1/2"Round300000000000000
    3/4"2 3/4"3/16"1/4"Round300000000000000
    3/4"5 3/8"1/4"1/2"Round30000000000000
    25/32"2 3/4"3/16"1/4"Round300000000000000
    25/32"5 3/8"1/4"5/8"Round300000000000000
    13/16"2 3/4"3/16"1/4"Round300000000000000
    13/16"5 3/8"1/4"5/8"Round30000000000000
    7/8"2 3/4"3/16"1/4"Round300000000000000
    7/8"5 3/8"1/4"3/4"Round300000000000000
    15/16"2 3/4"3/16"1/4"Round300000000000000
    15/16"6 1/8"1/4"3/4"Round300000000000000
    1"2 3/4"3/16"1/4"Round300000000000000
    1"6 3/8"5/16"3/4"Round30000000000000
    1 1/8"6 3/8"5/16"1"Round300000000000000
     
    C5 Carbide
    1/4"3 13/16"3/32"15/64"Round30000000000000
    9/32"3 13/16"3/32"17/64"Round300000000000000
    5/16"3 13/16"3/32"19/64"Round300000000000000
    11/32"3 13/16"3/32"5/16"Round300000000000000
    3/8"4 1/16"5/32"5/16"Round30000000000000
    13/32"4 1/16"5/32"3/8"Round300000000000000
    7/16"4 1/16"5/32"3/8"Round30000000000000
    15/32"4 5/16"3/16"7/16"Round300000000000000
    1/2"4 5/16"3/16"7/16"Round30000000000000
    17/32"4 5/16"3/16"1/2"Round300000000000000
    9/16"4 5/16"3/16"1/2"Round30000000000000
    19/32"5 1/8"3/16"1/2"Round300000000000000
    5/8"5 1/8"3/16"1/2"Round30000000000000
    21/32"5 1/8"3/16"1/2"Round300000000000000
    11/16"5 1/8"3/16"1/2"Round300000000000000
    23/32"5 3/8"1/4"1/2"Round300000000000000
    3/4"5 3/8"1/4"1/2"Round30000000000000
    25/32"5 3/8"1/4"5/8"Round300000000000000
    13/16"5 3/8"1/4"5/8"Round30000000000000
    7/8"5 3/8"1/4"3/4"Round300000000000000
    15/16"6 1/8"1/4"3/4"Round300000000000000
    1"6 3/8"5/16"3/4"Round30000000000000
    1 1/8"6 3/8"5/16"1"Round300000000000000
     

    Changeable-Pilot Counterbores Sets

    Image of Product. Front orientation. Counterbores. Changeable-Pilot Counterbores Sets.
    A handful of counterbores and changeable pilots give you the versatility of dozens of normal counterbores. For each hole, mix and match counterbores and pilots to correspond with your screw-head and screw-shank diameter.
    High-Speed Steel—Durable and wear resistant, these counterbores make accurate cuts in most materials without chipping or cracking.
    Body Dia.
    No. of
    Pieces
    Shank
    Type
    Includes
    Container
    Type
    Each
    Uncoated High-Speed Steel
    1/4", 5/16", 3/8", 7/16", 1/2"5Round10 PilotsWood Case00000000000000
     

    Adjustable-Diameter Counterbores

    Skip buying different tools to counterbore multiple diameters. Use the set screw on these counterbores to adjust the blades to the diameter you need.
    The included replaceable pilot has the minimum pilot head diameter recommended for use with these counterbores. If your application requires a larger pilot head diameter, choose a Steel Pilot for Changeable-Pilot Counterbores with the same shank diameter as the included pilot. These counterbores require rigid tool holding to prevent breakage and are not for use with hand-held tools.
    High-Speed Steel Blade
    Image of Product. Front orientation. Counterbores. Adjustable-Diameter Counterbores, Round Shank.
    Image of Product. Front orientation. Counterbores. Adjustable-Diameter Counterbores, Morse Taper Shank.

    Round Shank

    Morse Taper Shank

    Durable and wear resistant, these blades make accurate cuts in most materials without chipping or cracking.
    Counterbores
    Replacement
    Counterbore Blades
    Shank
    Body Dia.
    Overall
    Lg.
    Dia.
    Type
    Machine
    Taper No.
    Pilot
    Lg.
    No. of
    Flutes
    Pilot Head
    Dia.
    Pilot Shank
    Dia.
    Each
    Pkg.
    Qty.
    Pkg.
    1" to 1 1/4"4"1/2"Round0.438"27/16"3/16"00000000000000200000000000000
    1 1/4" to 1 5/8"4 3/8"1/2"Round0.563"29/16"1/4"000000000000020000000000000
    2 1/8" to 2 7/8"6"Morse TaperMorse 30.750"23/4"3/8"000000000000020000000000000
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