31 ga Drill Bits | McMaster-Carr

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Drill Bit Size

0.35 mm to 2.5 mm (Increments of 0.05 mm)

1", 1 1/32", 1 1/16", 1 1/8", 1 5/32", 1 3/16", 1 1/4", 1 5/16", 1 3/8", 1 7/16", 1 1/2"

1.0 mm to 10.0 mm (Increments of 0.5 mm)

1.0 mm to 13.0 mm (Increments of 0.5 mm)

1.0 mm to 5.9 mm (Increments of 0.1 mm)

1.0 mm to 6.9 mm (Increments of 0.1 mm)

1.0 mm to 7.0 mm (Increments of 0.5 mm)

1/16" to 1/2" (Increments of 1/64")

1/16" to 1/2" (increments of 1/32")

1/16" to 1/4" (Increments of 1/64")

1/16" to 3/8" (Increments of 1/64")

1/2" to 1" (Increments of 1/64")

1/64" to 1/4" (increments of 1/64")

2.6 mm to 10.0 mm (Increments of 0.1 mm)

6.0 mm to 10.0 mm (Increments of 0.1 mm)

9/16" to 1" (increments of 1/16")

33/64" to 63/64" (Increments of 1/64")

Decimal Size Equivalent

Length Class

Finish

Titanium Aluminum Nitride (TiAlN) Coated

Titanium Nitride (TiN) Coated

For Use On

Material

Point Angle

Shank Size

Drill Bit Point Type

Overall Length

Number of Flutes

Maximum Drilling Depth

Shank Type

Flute Direction

Sold As

Flute Type

For Use With

Bit Style

Length

REACH

RoHS

Export Control Classification Number (ECCN)

EAR99

DFARS Specialty Metals

Compliant

Exempt

Not Compliant

Mounting Hole Diameter

Specifications Met

46 Products

About Drill Bits

Compare material, finish, length class, and decimal size equivalents.

Drill Bits

Sold Individually

High-Speed Steel Drill Bits

Cut holes in a variety of metals, from the softest aluminum to the hardest steel

7 products

Cobalt Steel Drill Bits

Tough and wear resistant to last at least twice as long as high-speed steel bits

5 products

Carbide Drill Bits

The hardest and most wear-resistant drill bits you can buy

2 products

Expanded-Shank Carbide Drill Bits

Make small holes using standard-size tools

3 products

Short-Flute High-Speed Steel Drill Bits

The rigidity of short-length bits without sacrificing reach

2 products

Carbide Drill Bits for Hardened Steel

The hardest and most wear-resistant bits handle the heavy pressure needed to penetrate hardened steel

2 products

High-Speed Steel Drill Bits for Plastic

Penetrate gradually to prevent cracking and chipping

1 product

Carbide Drill Bits for Carbon Fiber, Fiberglass, and Graphite

Drill abrasive materials cleanly

1 product

Short-Flute Cobalt Steel Drill Bits

Combine the toughness and wear resistance of cobalt with short flutes for rigidity

2 products

Chip-Clearing High-Speed Steel Drill Bits

Prevent clogs and dissipate heat when drilling most metals

4 products

Chip-Clearing Cobalt Steel Drill Bits

Avoid clogs and dissipate heat with bits that last at least twice as long as high-speed steel

1 product

Left-Hand High-Speed Steel Drill Bits

Remove stripped screws with flutes that spiral in reverse from other bits

1 product

Carbide-Tipped Drill Bits

Stronger than cobalt and high-speed steel, bits stay sharp at high temperatures

2 products

Short-Flute Carbide-Tipped Drill Bits

Our strongest short-flute bits stay sharp when drilling abrasive materials, such as titanium

1 product

Smooth-Finish Carbide Drill Bits

More cutting edges for a consistent finish

1 product

Other Products

Drill Bit Size Gauges

Match your drill bit to one of the holes to confirm its size

1 product

Threaded Inserts

Create new threads or repair stripped threads

7 products

Drill Stops

Limit how far bits can drill to create identical hole depths every time

1 product

Steel

Strong, machinable, and weldable—all with material certificates for traceability

2 products