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Counterbore Type
About Counterbores
Create flat-bottomed holes, so your screw heads sit flush, recessed, or slightly raised.
Built-In-Pilot Counterbore Sets
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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 | Each | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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Uncoated High-Speed Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
No. 4, No. 5, No. 6, No. 8, No. 10, 1/4", 5/16", 3/8", 7/16", 1/2" | 10 | Round | 4 | 2919A12 | 0000000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Drill-Point Counterbore Sets
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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.
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
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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.
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
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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.
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
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Durable and wear resistant, these counterbores make accurate cuts in most materials without chipping or cracking.
Uncoated | |||||||||
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For Screw Size | Body Dia. | Overall Lg. | Shank Type | No. of Flutes | Pilot Lg. | Each | |||
No. 6 | 0.241" | 2 5/8" | Round | 2 | 0.230" | 2909A17 | 000000 | ||
Oversized Counterbore Sets
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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.
Counterbore Drill Bits
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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. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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For Screw Size | Body | Step | Step | Overall | Point Angle | For Use On | Each | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Uncoated High-Speed Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
No. 6 | 0.250" | 0.15" | 1/2" | 4" | 118° | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 8914A31 | 000000 | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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
Oversized Long-Life Counterbore Drill Bits
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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. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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For Screw Size | Body | Step | Step | Overall | No. of Flutes | Point Angle | For Use On | Each | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Uncoated High-Speed Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
1/64" Oversize | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
No. 6 | 0.234" | 0.146" | 5/16" | 2 7/16" | 2 | 118° | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 29525A41 | 000000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Long-Life Counterbore Drill Bits
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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. | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
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For Screw Size | Body | Step | Step | Overall | No. of Flutes | Point Angle | For Use On | Each | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
Uncoated High-Speed Steel | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
No. 6 | 0.228" | 0.141" | 5/16" | 3 7/8" | 2 | 118° | Aluminum, Brass, Bronze, Iron, Plastic, Stainless Steel, Steel | 29525A42 | 000000 | ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||