4 1/4" Drill Bits | McMaster-Carr

	REACH (Registration, Evaluation, Authorization and Restriction of Chemicals) REACH (Registration, Evaluation, Authorization and Restriction of Chemicals)

REACH Compliant

	Specifications Met Specifications Met

NAS

DIN

ASME

ANSI

	Number of Flutes Number of Flutes

	2		3

	Body Diameter Body Diameter

0.281"

0.290"

	For Screw Size For Screw Size

136 Products

Drill Bit Decimal Size Equivalents

About Drill Bits

Drill Bits

These jobbers'-length bits have the rigidity and length required for most applications.

Short-Length Drill Bits

Also known as screw-machine and stub-length bits, these provide maximum rigidity for drilling straighter holes than jobbers'- and maintenance-length drill bits.

Extended-Length Drill Bits

Maintenance-Length Drill Bits

Also known as mechanics' bits, these are shorter and more rigid than jobbers’ bits but longer than short‐length bits.

Chip-Clearing Drill Bits

These jobbers'-length bits have the rigidity and length required for most applications.

Drill Bits for Precise Holes

Specially-designed flutes keep these bits centered as they drill, resulting in straighter, rounder holes with tighter tolerances. Also known as double-margin drill bits.

Cobalt Steel Drill Bits

Short-Flute Cobalt Steel Drill Bits

The short flutes on these jobbers'-length bits provide increased rigidity for drilling straighter holes.

Extended-Length Cobalt Steel Drill Bits

Chip-Clearing Cobalt Steel Drill Bits

The parabolic spiral flutes lift chips out of the hole, reducing clogging and improving coolant flow.

Carbide Drill Bits

These jobbers'-length bits have the rigidity and length required for most applications.

Smooth-Finish Carbide Drill Bits

Three cutting edges instead of the typical two enable these bits to drill holes with a smoother finish than other bits.

Carbide Drill Bits with Coolant Holes

Holes in these bits allow coolant to be run through the tool for more efficient chip evacuation. Use them in CNC machines with coolant-through technology.

Carbide Drill Bits for Precise Holes

Specially-designed flutes keep these bits centered as they drill, resulting in straighter, rounder holes with tighter tolerances. Also known as double-margin drill bits.

Carbide-Tipped Drill Bits

These jobbers'-length bits have the rigidity and length required for most applications.

Short-Length Carbide-Tipped Drill Bits

Also known as screw-machine and stub-length bits, these provide maximum rigidity for drilling straighter holes than jobbers'-length drill bits.

1/4" Diameter Reduced-Shank Drill Bits

Hex-Shank Drill Bits

Insert these bits directly into power screwdrivers, impact drivers, and other tools that accept 1/4" hex shanks.

Cobalt Steel Hex-Shank Drill Bits

In addition to resisting heat and wear better than high-speed steel drill bits, these can also run up to 25% faster and have a longer tool life. Insert them into power screwdrivers, impact drivers, and other tools that accept hex shanks.

Round- and Hex-Shank Masonry
Drill Bits for Hammer Drills

These bits have a round or hex shank that fits into the three-jaw chuck on a hammer drill.

Drill Bits for Precise Holes in Wood

Three sharp points allow these bits to drill accurate straight and overlapping holes, even across the grain. Also known as brad-point bits.

Drill Bits for Wood Screws

These bits are cut to match a wood screw’s thread and diameter, resulting in a perfect fit for a screw. They produce clean edges when cutting soft and hard wood.

Carbide-Tipped Drill Bits for Hardened Steel

Carbide-tipped bits maintain their sharp edges when drilling hard material. They are for use in both hand-held drilling and machine-tool applications.

Drill Bits for Plastic

The sharp point allows for gradual penetration to reduce friction and eliminate cracking and chipping when drilling in plastic.

Drill Bits for Carbon Fiber, Fiberglass, and Graphite

These jobbers'-length bits have the rigidity and length required for most applications.

Cobalt Steel Drill Bits for Stainless Steel and Nickel

Cobalt steel bits are heat resistant and maintain their sharp edges when drilling hard material. They are for use in both hand-held drilling and machine-tool applications.

Drill Bits for Aluminum, Brass, and Bronze

Because softer metal, like aluminum, brass, and bronze, can clog a bit, the flutes on these bits lift chips out of the hole. Also known as slow-spiral drill bits.

High-Speed Steel Left-Hand Drill Bits

Use for drilling in most metal.

Replaceable Carbide-Insert Drill Bits

Use these bits to drill a large number of holes with high precision. When the cutting edges dull, replace the carbide inserts (sold separately) instead of the entire bit.

Countersinking Drill Bits

Countersinking Drill Bits for Screws

Also known as step drill bits. The 82° countersink angle is compatible with the profile of flat- and oval-head inch screws.

Countersinking Drill Bits for Taps

Also called subland drill bits. The 90° countersink angle guides the tap into the hole.

Counterboring Drill Bits

Often called step drill bits.

Oversized Long-Life Counterboring Drill Bits

Often used with screw holes in misaligned sheets or layers of material.

Ball-End Driver Shafts

Create your own tool by attaching these shafts to a handle, or use with socket wrenches and power tools. They have a ball end that allows angled entry to make good contact with the recess when a standard-tip shaft can’t.

High-Speed Tool Steel

Hardened Undersized High-Speed M2 Tool Steel Rods

These rods, also known as drill blanks, have an undersized diameter for machining your own jobbers'-length drill bits.

Hardened Oversized High-Speed M2 Tool Steel Rods

Also known as reamer blanks, these rods are hardened for increased abrasion and impact resistance.

Hardened High-Speed M42 Tool Steel

Also known as cobalt steel, this M42 tool steel maintains its hardness in high-speed cutting applications that generate intense heat. Use it to make tools for cutting extremely hard materials.

Cobalt Steel Drill/Mill End Mills

Made of cobalt steel, these end mills have good heat and wear resistance, so they can run at high speeds in hard material. A 90° pointed tip allows them to be used for drilling as well as for slotting, profiling, chamfering, and spotting cuts.

Drill Bit Decimal Size Equivalents