McMaster-Carr logo
    Forward
    Enter e-mail addresses in the fields below
    Message
    Cancel
    Print
    How can we improve?
    Comments
    E-mail address (if you would like a response)
    39 Products
    About Countersinks
    industrial info icon

    Choose the right countersink angle, body diameter, and number of flutes for your application.

    Drill-Point Countersink Sets for Screws

    Image of Product. Front orientation. Countersinks. Drill-Point Countersink Sets for Screws.
    Save time by drilling and countersinking your pilot hole in one pass for a range of screw sizes. These countersinks have a small drill point to drill new pilot holes topped with cone-shaped recesses for screw heads.
    High-Speed Steel—These versatile, wear-resistant countersinks cut cleanly in most materials, including plastic, aluminum, and steel.
    Manufacturer—We source from trusted manufacturers who vet raw materials for purity and use diamond grinding wheels to machine precise edges. This keeps cutting surfaces smooth and free of microscopic burrs. Because our suppliers clean their wheels more often than other manufacturers, each countersink is consistently ground to create uniform holes every time.
    82°
    Countersink Angle
    No. of
    Flutes
    No. of
    Pieces
    For Screw Size
    Finish
    Shank
    Type
    Container
    Type
    Mfr.
    Each
    High-Speed Steel
    28No. 5, No. 6, No. 8, No. 10, No. 12, 1/4", 5/16", 3/8"
    		UncoatedRoundPlastic CaseLink Industries28145A610000000
     

    Quick-Change Hex Drill-Bit Countersinks for Wood and Plastic

    Switch bits instead of tools to simplify jobs. These snap directly into drills, power screwdrivers, and other tools that accept a 1/4" hex shank. You can slide the countersink up and down the drill bit and then secure it with a set screw, so one tool will drill countersunk holes for screws of different lengths. These countersinks cut a smooth and even finish in wood and plastic on the first pass.
    High-Speed Steel
    Image of Product. Front orientation. Countersinks. For Cutting Screw Holes, Drill-Bit Countersink, For Wood, Straight Flute, Quick-Change Hex Shank, Sold Individually, 1 Countersinking End, 2 Flutes.

    2 Flutes

    The choice if you're countersinking lots of holes, these wear-resistant countersinks cut faster and last longer than carbon steel.
    Manufacturer—We source from trusted manufacturers who vet raw materials for purity and use diamond grinding wheels to machine precise edges. This keeps cutting surfaces smooth and free of microscopic burrs. Because our suppliers clean their wheels more often than other manufacturers, each countersink is consistently ground to create uniform holes every time.
    Countersinks
    Replacement
    Drill Bits
    For
    Screw Size
    Uncoated
    Body
    Dia.
    Max. Hole
    Drilling Dp.
    Hard
    Wood
    Soft
    Wood
    Overall
    Lg.
    Shank
    Size
    Shank Type
    Mfr.
    Each
    Each
    2 Flutes
     
    82° Countersink Angle
    1/2"1"No. 8
    		No. 10
    		2 31/32"1/4"Quick-Change HexMake It Snappy Tools2747A24000008870A1800000
    1/2"1"No. 10
    		No. 12
    		3 3/32"1/4"Quick-Change HexMake It Snappy Tools2747A2500008870A190000
     

    Drill-Point Countersinks for Screws

    Save time by drilling a pilot hole and countersinking in a single step. These countersinks have a small drill point to drill new pilot holes topped with cone-shaped recesses for screw heads.
    High-Speed Steel
    Image of Product. Front orientation. Countersinks. Drill-Point Countersinks for Screws, 2 Flutes.

    2 Flutes

    These versatile, wear-resistant countersinks cut cleanly in most materials, including plastic, aluminum, and steel.
    Number of Flutes—Countersinks with fewer flutes reduce chatter, so you can run them at high speeds. Countersinks with a higher number of flutes remove more material per revolution, leaving a smoother finish and extending tool life.
    Manufacturer—We source from trusted manufacturers who vet raw materials for purity and use diamond grinding wheels to machine precise edges. This keeps cutting surfaces smooth and free of microscopic burrs. Because our suppliers clean their wheels more often than other manufacturers, each countersink is consistently ground to create uniform holes every time.
    Dia.
    Uncoated
    Body
    Shank
    Drill Tip
    Dia.
    For Screw
    Size
    Overall
    Lg.
    Shank
    Type
    Mfr.
    Each
    2 Flutes
     
    82° Countersink Angle
    7/16"1/4"0.192"No. 10
    		2"RoundLink Industries28145A44000000
     

    Countersink Drill Bits for Screws

    Image of Product. Front orientation. Contains Annotated. Countersink Drill Bits. Countersink Drill Bits for Screws.
    Also known as step drill bits, these bits countersink as they drill. The 82° countersink angle is compatible with the profile of flat- and oval-head inch screws. After multiple sharpenings, the drill bit diameter may become smaller.
    Dia.
    Lg.
    82°
    Countersink Angle
    For Screw
    Size
    Body
    Step
    Step
    Overall
    Shank
    Dia.
    Point
    Angle
    For Use On
    Mfr.
    Each
    Uncoated High-Speed Steel
     
    2 Flutes
    No. 10
    		0.386"0.196"5/8"5 1/8"0.3860"118°Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, SteelRepublic Drill8914A53000000
     

    Drill-Bit Countersinks for Wood and Plastic

    These countersinks attach at various points along the drill bit, so one tool will drill countersunk holes for screws of different lengths. They're designed to cut a smooth and even finish in wood and plastic on the first pass.
    High-Speed Steel
    Image of Product. Front orientation. Countersinks. Drill-Bit Countersink, 1 Countersinking End, For Wood, For Cutting Screw Holes, Sold Individually, Straight Flute, 4 Flutes.

    4 Flutes

    The choice if you're countersinking lots of holes, these wear-resistant countersinks cut faster and last longer than carbon steel.
    Manufacturer—We source from trusted manufacturers who vet raw materials for purity and use diamond grinding wheels to machine precise edges. This keeps cutting surfaces smooth and free of microscopic burrs. Because our suppliers clean their wheels more often than other manufacturers, each countersink is consistently ground to create uniform holes every time.
    Countersinks
    Counterbore Collars
    Uncoated
    Body
    Dia.
    For Drill
    Bit Size
    For Screw
    Size
    Overall
    Lg.
    Mfr.
    Each
    OD
    Wd.
    Each
    4 Flutes
     
    82° Countersink Angle
    3/8"13/64"No. 10
    		7/8"W. L. Fuller2910A290000005/8"1/4"2903A1300000
    7/16"13/64"No. 10
    		7/8"W. L. Fuller2910A180000011/16"1/4"2903A140000
    1/2"13/64"No. 10
    		7/8"W. L. Fuller2910A19000003/4"1/4"2903A150000
     
    90° Countersink Angle
    3/8"13/64"No. 10
    		7/8"W. L. Fuller2910A89000005/8"1/4"2903A130000
    7/16"13/64"No. 10
    		7/8"W. L. Fuller2910A780000011/16"1/4"2903A140000
    1/2"13/64"No. 10
    		7/8"W. L. Fuller2910A79000003/4"1/4"2903A150000
     
    Carbon Steel
    Image of Product. Front orientation. Countersinks. Drill-Bit Countersink, 1 Countersinking End, For Wood, For Cutting Screw Holes, Sold Individually, Straight Flute, 4 Flutes.

    4 Flutes

    Stronger than high-speed steel, so it will cut through harder materials. However, high-speed steel is more precise, lasts longer, and cuts at higher speeds.
    Manufacturer—We source from trusted manufacturers who vet raw materials for purity and use diamond grinding wheels to machine precise edges. This keeps cutting surfaces smooth and free of microscopic burrs. Because our suppliers clean their wheels more often than other manufacturers, each countersink is consistently ground to create uniform holes every time.
    Countersinks
    Counterbore Collars
    Uncoated
    Body
    Dia.
    For Drill
    Bit Size
    For Screw
    Size
    Overall
    Lg.
    Mfr.
    Each
    OD
    Wd.
    Each
    4 Flutes
     
    82° Countersink Angle
    3/8"13/64"No. 10
    		7/8"W. L. Fuller2785A26000005/8"1/4"2903A1300000
    7/16"13/64"No. 10
    		7/8"W. L. Fuller2785A310000011/16"1/4"2903A140000
    1/2"13/64"No. 10
    		7/8"W. L. Fuller2785A38000003/4"1/4"2903A150000
     

    Drill-Point Counterbore Sets

    Image of Product. Front orientation. Counterbores. Drill-Point Counterbore Sets.
    Skip a step when installing screws of various thread diameters in metal. With a sharp point on the tip, these counterbores drill a pilot hole topped with a flat recess for the screw head. That's faster and more accurate than switching to a counterbore in between passes with your drill bit.
    High-Speed Steel—Durable and wear resistant, these counterbores make accurate cuts in most materials without chipping or cracking.
    For Screw Size
    No. of
    Pieces
    Shank
    Type
    No. of
    Flutes
    Container
    Type
    Mfr.
    Each
    Uncoated High-Speed Steel
    No. 5, No. 6, No. 8, No. 10, 1/4", 5/16", 3/8", 7/16", 1/2"
    		9Round2Plastic CaseLink Industries9940N1110000000
    No. 5, No. 6, No. 8, No. 10, 1/4", 5/16", 3/8", 7/16", 1/2"
    		9Round2Plastic CaseLink Industries9940N112000000
     

    Built-in-Pilot Counterbore Sets

    Image of Product. Front orientation. Counterbores. Built-in-Pilot Counterbore Sets.
    Create flat, close-fitting recesses for a range of screw-head sizes. The pilot centers and stabilizes the counterbore for an accurate cut and even surface on the first try.
    High-Speed Steel—Durable and wear resistant, these counterbores make accurate cuts in most materials without chipping or cracking.
    For Screw Size
    No. of
    Pieces
    Shank
    Type
    No. of
    Flutes
    Mfr.
    Each
    Uncoated High-Speed Steel
    No. 4, No. 5, No. 6, No. 8, No. 10, 1/4", 5/16", 3/8", 7/16", 1/2"
    		10Round4Alvord-Polk Tool2919A120000000
     

    Quick-Change Combination Countersinking Drill/Screwdriver Bits

    Image of ProductInUse. Front orientation. Contains Annotated, Border, MultipleImages. Drill/Screwdriver Bits. Quick-Change Combination Countersinking Drill/Screwdriver Bits.
    Image of Product. Front orientation. Drill/Screwdriver Bits. Quick-Change Combination Countersinking Drill/Screwdriver Bits.
    Drill, countersink, and drive screws without switching three separate bits in and out of your power tool. With a single hand, flip between drilling countersunk holes and driving screws. The countersinking drill and screwdriver bit are secured with set screws, so you can switch them out for any bits with a 1/4” hex shank.
    The countersinking drill has an 82° angle, allowing inch-sized flat- and oval-head screws to sit flush with the surface.
    Drill/Screwdriver Bits
    Replacement
    1/8" Drill Bits
    For Screw
    Size
    Drill Bit
    Size
    Countersink
    Body Dia.
    Max. Hole
    Drilling Dp.
    Countersink
    Angle
    Screwdriver
    Bit Size
    For Drive
    Style
    Adapter Hex
    Shank Size
    Adapter
    Lg.
    For Use On
    Each
    Each
    Black-Oxide High-Speed Steel Countersink
     
    4 Countersink Flutes
    No. 10
    		1/8"
    		3/8"2 1/4"82°
    		No. 2Phillips
    		5/16"3 3/4"Aluminum, Fiberglass, Plastic, Wood3471N130000003471N1600000
     

    Oversized Counterbores

    Designed to give screw heads a slightly loose fit, these counterbores are a bit wider than standard sizes. The extra clearance prevents binding and leaves room for a seal or O-ring around the screw head.
    High-Speed Steel
    Image of Product. Front orientation. ZoomedIn view. Counterbores. Oversized Counterbores.
    Durable and wear resistant, these counterbores make accurate cuts in most materials without chipping or cracking.
    Titanium Nitride (TiN) Coated—Withstand heat, corrosion, and abrasion for longer than uncoated counterbores, so the cutting edges stay sharper.
    Pilot
    Shank
    Uncoated
    Titanium Nitride
    (TiN) Coated
    For Screw
    Size
    Body
    Dia.
    Dia.
    Lg.
    Overall
    Lg.
    Dia.
    Type
    No. of
    Flutes
    Mfr.
    Each
    Each
     
    1/64" Oversize
    No. 10
    		0.330"0.206"0.281"5 1/4"9/32"Round4Alvord-Polk Tool2919A5500000028225A55000000
     
    1/32" Oversize
    No. 10
    		0.345"0.221"0.281"5 1/4"9/32"Round4Alvord-Polk Tool2919A750000028225A7500000
     

    Oversized Long-Life Counterbore Drill Bits

    Image of Product. Front orientation. Contains Annotated. Counterbore Drill Bits. Oversized Long-Life Counterbore Drill Bits.
    These counterbores are often used when screw holes in sheets or layers are misaligned. Also known as subland drill bits, they last longer than standard counterbore drill bits because the diameter stays the same after sharpening. They drill and counterbore at the same time. After drilling and counterboring, tap the hole and install your fastener. The diameters account for the 1/32” or 1/64” oversized diameter rating.
    Dia.
    Lg.
    For Screw
    Size
    Body
    Step
    Step
    Overall
    No. of
    Flutes
    Point
    Angle
    For Use On
    Mfr.
    Each
    Uncoated High-Speed Steel
     
    1/64" Oversize
    No. 10
    		0.328"0.206"5/8"4 5/8"2118°Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, SteelRTS Cutting Tools29525A49000000
    No. 10
    		0.344"0.206"1/2"4 3/4"2118°Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, SteelRTS Cutting Tools29525A5100000
     

    Built-in-Pilot Counterbores

    The pilot centers the counterbore and prevents wobbling for an accurate cut on the first try. With dimensions that match standard screw-head diameters and thread diameters, this is your plug-and-play option for pilot-driven counterbores.
    High-Speed Steel
    Image of Product. Front orientation. ZoomedIn view. Counterbores. Built-in-Pilot Counterbores.
    Durable and wear resistant, these counterbores make accurate cuts in most materials without chipping or cracking.
    Titanium Nitride (TiN) Coated—Withstand heat, corrosion, and abrasion for longer than uncoated counterbores, so the cutting edges stay sharper.
    Pilot
    Shank
    Uncoated
    Titanium Nitride
    (TiN) Coated
    For Screw
    Size
    Body
    Dia.
    Dia.
    Lg.
    Overall
    Lg.
    Dia.
    Type
    No. of
    Flutes
    Mfr.
    Each
    Each
    No. 10
    		0.314"0.19"0.281"5 1/4"9/32"Round4Alvord-Polk Tool2919A3500000028225A35000000
     

    Counterbores for High-Profile Rounded-Head Screws

    Cut flat, close-fitting recesses for fillister-head screws. These counterbores cut deeply enough for screws with tall head profiles to sit flush with the surface.
    High-Speed Steel
    Image of Product. Front orientation. Counterbores. Counterbores for High-Profile Rounded-Head Screws.
    Durable and wear resistant, these counterbores make accurate cuts in most materials without chipping or cracking.
    Uncoated
    For Screw
    Size
    Body
    Dia.
    Overall
    Lg.
    Shank
    Type
    No. of
    Flutes
    Pilot
    Lg.
    Mfr.
    Each
    No. 10
    		0.328"2 7/8"Round20.190"Republic Drill2909A19000000
     

    Drill-Point Counterbores

    Skip a step when installing screws in metal. With a sharp point on the tip, these counterbores drill a pilot hole topped with a flat recess for the screw head. That's faster and more accurate than switching to a counterbore in between passes with your drill bit.
    High-Speed Steel
    Image of Product. Front orientation. Counterbores. Drill-Point Counterbores.
    Durable and wear resistant, these counterbores make accurate cuts in most materials without chipping or cracking.
    Shank
    Uncoated
    For Screw
    Size
    Body
    Dia.
    Overall
    Lg.
    Dia.
    Type
    No. of
    Flutes
    Max. Hole
    Drilling Dp.
    Mfr.
    Each
    No. 10
    		0.332"1 1/2"5/16"Round20.312"Link Industries29445A14000000
    No. 10
    		0.332"2 1/4"3/8"Round20.6"Link Industries29445A31400000
     

    Counterbore Drill Bits

    Image of Product. Front orientation. Contains Annotated. Counterbore Drill Bits. Counterbore Drill Bits.
    Often called step drill bits, these drill and counterbore holes at the same time. After drilling and counterboring, tap the hole and install your fastener. The body diameter may decrease after multiple sharpenings.
    Dia.
    Lg.
    For Screw
    Size
    Body
    Step
    Step
    Overall
    Point
    Angle
    For Use On
    Mfr.
    Each
    Uncoated High-Speed Steel
    No. 10
    		0.332"0.204"5/8"4 3/4"118°Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, SteelRepublic Drill8914A33000000
     

    Oversized Counterbore Sets

    Image of Product. Front orientation. Counterbores. Oversized Counterbore Sets.
    Designed to give screw heads a slightly loose fit, these counterbores are a bit wider than standard sizes. The extra clearance prevents binding and leaves room for a seal or O-ring around the screw head.
    High-Speed Steel—Durable and wear resistant, these counterbores make accurate cuts in most materials without chipping or cracking.
    For Screw Size
    No. of
    Pieces
    Oversize
    Amount
    Shank
    Type
    No. of
    Flutes
    Mfr.
    Each
    Uncoated High-Speed Steel
    No. 4, No. 5, No. 6, No. 8, No. 10, 1/4", 5/16", 3/8", 7/16", 1/2"
    		101/64"Round4Alvord-Polk Tool2919A140000000
    No. 4, No. 5, No. 6, No. 8, No. 10, 1/4", 5/16", 3/8", 7/16", 1/2"
    		101/32"Round4Alvord-Polk Tool2919A16000000
     

    Long-Life Counterbore Drill Bits

    Image of Product. Front orientation. Contains Annotated. Counterbore Drill Bits. Long-Life Counterbore Drill Bits.
    Also known as subland drill bits, these last longer than standard counterbore drill bits because the diameter stays the same after sharpening. They drill and counterbore at the same time. After drilling and counterboring, tap the hole and install your fastener.
    Dia.
    Lg.
    For Screw
    Size
    Body
    Step
    Step
    Overall
    No. of
    Flutes
    Point
    Angle
    For Use On
    Mfr.
    Each
    Uncoated High-Speed Steel
    No. 10
    		0.313"0.190"1/2"2 13/16"2118°Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, SteelRTS Cutting Tools29525A48000000
     
    back to top