4.0 mm Drill Bits | McMaster-Carr

Extended Length—Drill through panels and thick workpieces with our longest bits. Their length is good for creating deep holes but makes them less rigid than other bits. As a result, they are more prone to wobbling or breaking, especially when drilling hard materials.

Black Oxide—The dark finish increases wear resistance and reduces friction to improve chip flow, so these bits can last 50% longer than uncoated bits.

Titanium Nitride (TiN) Coated—Drill at higher speeds and last longer than uncoated and oxide-coated bits, especially on tough materials like hardened steel and nickel.

Gold Oxide—Like black oxide, this finish adds wear resistance and reduces friction for improved chip flow. Because it’s less prone to flaking off, it offers better rust protection when bits aren't in use.

Uncoated—The most economical option, uncoated bits perform best when used on low-carbon steel and aluminum. Polished to reduce friction, they're also known as bright finish bits.

					Shank			Each		Package
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size	Drill Bit Point Type		Each	Pkg. Qty.		Pkg.
Jobbers' Length







				Black Oxide

				4.0	0.1575"	75	35	Round	4 mm	Standard	2958A72	00000	10	2958A722	000000




						Titanium Nitride (TiN) Coated

						4.0	0.1575"	75	37	Round	4 mm	Standard	8950A15	0000	—	———	0




								Gold Oxide

								4.0	0.1575"	83	49.2	Round	4 mm	Split	30565A261	0000	10	30565A429	00000




										Uncoated

										4.0	0.1575"	83	42.9	Round	4 mm	Standard	2951A132	0000	—	———	0


										Short Length







														Black Oxide

														4.0	0.1575"	55	13.9	Round	4 mm	Split	28255A33	0000	—	———	0




																Titanium Nitride (TiN) Coated

																4.0	0.1575"	56	22.1	Round	4 mm	Split	2979N19	0000	—	———	0


																Extended Length







																				Black Oxide

																				4.0	0.1575"	160	91.9	Round	4 mm	Standard	88455A42	00000	—	———	0


4.0	0.1575"																			200	141.9	Round	4 mm	Standard	88455A62	00000	—	———	0
4.0	0.1575"																			315	241.9	Round	4 mm	Standard	88455A72	00000	—	———	0




		Uncoated

		4.0	0.1575"																	119	69.7	Round	4 mm	Standard	3083A144	0000	—	———	0

High-Speed Steel Step Drill Bits


	Standard

Drill multiple hole sizes using only one bit. These have steps with progressively larger diameters—the deeper they drill, the bigger the hole. Count the steps as you drill to achieve the proper size. These bits also deburr as they cut, so they're good for thin materials like sheet metal and plastic panels. Wear and heat resistant, high-speed steel is versatile for use on a range of materials.

Black Oxide—The dark finish increases wear resistance and reduces friction to improve chip flow, so these bits can last 50% longer than uncoated bits.

Titanium Aluminum Nitride (TiAlN) Coated—The hardest and most wear-resistant coating, especially at high temperatures. These bits are best for hard and abrasive materials, such as iron and titanium.

Uncoated—The most economical option, uncoated bits perform best when used on low-carbon steel and aluminum. Polished to reduce friction, they're also known as bright finish bits.

			Shank
Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Type	Size	Drill Bit Point Type		Each







			Black Oxide

			4.0, 5.0, 6.0, 6.5, 8.0, 9.0, 10.0, 11.0, 12.0	0.1575", 0.1969", 0.2362", 0.2559", 0.315", 0.3543", 0.3937", 0.4331", 0.4724"	65	Round/3-Flat	6.4 mm	Standard	5910N19	000000


			4.0, 6.0, 8.0, 10.0, 12.0, 14.0, 16.0, 18.0, 20.0	0.1575", 0.2362", 0.315", 0.3937", 0.4724", 0.5512", 0.6299", 0.7087", 0.7874"	65	Round/3-Flat	6.4 mm	Standard	5910N21	00000




					Titanium Aluminum Nitride (TiAlN) Coated

					4.0, 6.0, 8.0, 10.0, 12.0, 14.0, 16.0, 18.0, 20.0	0.1575", 0.2362", 0.315", 0.3937", 0.4724", 0.5512", 0.6299", 0.7087", 0.7874"	76	Quick-Change Hex	6.35 mm	Standard	89275A36	00000


					4.0, 14.0, 16.0, 18.0, 20.0, 22.0, 24.0, 26.0, 28.0, 30.0	0.1575", 0.5512", 0.6299", 0.7087", 0.7874", 0.8661", 0.9449", 1.0236", 1.1024", 1.1811"	95	Hex	6.35 mm	Standard	89275A37	000000




							Uncoated

							4.0, 6.0, 8.0, 10.0, 12.0, 14.0, 16.0, 18.0, 20.0, 22.0	0.1575", 0.2362", 0.315", 0.3937", 0.4724", 0.5512", 0.6299", 0.7087", 0.7874", 0.8661"	76	Hex	10 mm	Standard	89275A14	00000

Cobalt Steel Drill Bits


Jobbers' Length Round Shank	Short Length Round Shank	Split

Tough and wear resistant, cobalt steel bits last at least twice as long as high-speed steel. They can also run up to 25% faster at higher temperatures without being damaged on hard materials, such as nickel.

Jobbers' Length—These bits have the balance of rigidity and length needed for most applications.

Short Length—The most rigid bits for drilling the straightest holes.

Titanium Nitride (TiN) Coated—Drill at higher speeds and last longer than uncoated and oxide-coated bits, especially on tough materials like hardened steel and nickel.

Uncoated—Polished to eject chips, these are also known as bright finish bits.

					Shank
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size	Drill Bit Point Type		Each
Jobbers' Length







				Titanium Nitride (TiN) Coated

				4.0	0.1575"	75	42.9	Round	4 mm	Split	5058N61	00000




						Titanium Aluminum Nitride (TiAlN) Coated

						4.0	0.1575"	75	37	Round	4 mm	Split	2753A167	00000




								Gold Oxide

								4.0	0.1575"	75	35	Round	4 mm	Split	29355A64	0000


								Short Length







												Titanium Nitride (TiN) Coated

												4.0	0.1575"	56	14	Round	4 mm	Split	2456N148	0000




														Uncoated

														4.0	0.1575"	56	14	Round	4 mm	Split	2456N121	0000

Carbide Drill Bits

The hardest and most wear-resistant drill bits you can buy. Carbide bits stay sharp at high temperatures and faster speeds for the best performance on hard and difficult-to-machine materials. They last 10 to 20 times longer than their closest alternative, cobalt steel. Carbide can be brittle, however, so these bits require a rigid machine tool holder to prevent breakage and should not be used in hand drilling applications.

Jobbers' Length—These bits have the balance of rigidity and length needed for most applications.

Short Length—The most rigid bits for drilling the straightest holes.

Titanium Nitride (TiN) Coated—Drill at higher speeds and last longer than uncoated bits, especially on materials like hardened steel, iron, and stainless steel.

Titanium Aluminum Nitride (TiAlN) Coated—No drill bits last longer. These are the best for high-speed, high-temperature drilling of very hard and abrasive materials, including titanium and fiberglass.

Uncoated—Excellent for a range of materials but won't last as long as coated bits.

					Shank
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size	Drill Bit Point Type		Each
Jobbers' Length
Round Shank






				Titanium Nitride (TiN) Coated

				4.0	0.1575"	63	35	Round	4 mm	Four Facet	3030A78	000000




						Uncoated

						4.0	0.1575"	63	28	Round	4 mm	Four Facet	3030A27	00000


						Short Length
						Round Shank






										Titanium Nitride (TiN) Coated

										4.0	0.1575"	63	19	Round	4 mm	Four Facet	27515A713	00000




												Titanium Aluminum Nitride (TiAlN) Coated

												4.0	0.1575"	63	19	Round	4 mm	Four Facet	8879A613	00000




														Uncoated

														4.0	0.1575"	63	19	Round	4 mm	Four Facet	2956A813	00000

Drill Bit Size Gauges

For

Metric

Measure drill bit sizes with these gauges.

For System of Measurement	For Use With	For Drill Bit Size, mm	Wd.	Ht.	Thk.	Material	Color	Mounting Hole Dia.		Each
Metric	Drills	1.5, 2.0, 2.25, 2.5, 2.75, 3.0, 3.25, 3.5, 3.75, 4.0, 4.25, 4.5, 4.75, 5.0, 5.25, 5.5, 6.0, 6.5, 7.0, 7.5, 8.0, 8.5, 9.0, 9.5, 10.0, 10.5, 11.0, 11.5, 12.0, 12.5	2 1/2"	6 1/2"	5/64"	Steel	Silver	1/8"	8986A64	000000

Left-Hand Cobalt Steel Drill Bits


Jobbers' Length Round Shank	Split

The flutes spiral in the opposite direction of other bits and stay sharp longer than high-speed steel. They’re primarily used to remove stripped screws. Choose a bit that’s slightly smaller than the diameter of the screw’s head. Set your power tool to rotate in reverse. Slowly drill in the center of the screw head, maintaining constant pressure. As the bit penetrates, it will catch onto the screw and reverse it out of the hole. If the screw is badly stripped, you might need to punch a starter hole. Also known as reverse-flute bits.

Jobbers' Length—These bits have the balance of rigidity and length needed for most applications.

Uncoated—Polished to eject chips, these are also known as bright finish bits.

					Shank				Each
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size	Drill Bit Point Type		1-9	10-Up
Jobbers' Length







				Uncoated

				4.0	0.1575"	83	54	Round	4 mm	Split	3474A54	000000	000000

Coolant-Fed Carbide Drill Bits


Jobbers' Length Round Shank	Maintenance Length Round Shank

The hardest and most wear-resistant bits, these deliver coolant to reduce heat and evacuate chips. They are designed for CNC machines that supply coolant through the spindle rather than an external source, such as a hose and nozzle. Coolant flows directly from holes in the bit's tip onto the drilling surface. This speeds up cuts and leads to excellent performance in deep holes and tough materials such as stainless steel and titanium.

Jobbers' Length—These bits have the balance of rigidity and length needed for most applications.

Maintenance Length—Shorter than jobbers' length, these bits are more rigid for less wobble when drilling hard material. Also known as mechanics’ bits.

					Shank
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size	Drill Bit Point Type		Each
Jobbers' Length







				Titanium Aluminum Nitride (TiAlN) Coated

				4.0	0.1575"	73	36.1	Round	6 mm	Four Facet	2396N257	000000


				Maintenance Length







								Titanium Aluminum Nitride (TiAlN) Coated

								4.0	0.1575"	67	23.9	Round	6 mm	Four Facet	2396N638	00000

High-Speed Steel Drill Bits for Plastic

The precision-ground, 60° point penetrates gradually to prevent cracking and chipping. It also reduces heat that can deform the material. Use these bits for drilling into acrylic, laminate, and other plastics. They're made of wear-resistant high-speed steel.

Jobbers' Length About Jobbers' Length

					Shank
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size, mm	Point Angle	Drill Bit Point Type		Each
Uncoated



		4.0	0.1575"	75	43	Round	4	60°	Standard	27465A413	00000

Carbide-Tipped Drill Bits

Jobbers' Length

Round Shank

Short Length

Round Shank


Standard	Split

Performance similar to solid carbide but at a lower price point. Like carbide bits, these are stronger than cobalt and high-speed steel and maintain their sharp edges when drilling abrasive material. However, when drilling tough metals like iron and hardened steel, upgrade to carbide for longer life.

Jobbers' Length—These bits have the balance of rigidity and length needed for most applications.

Short Length—The most rigid bits for drilling the straightest holes.

					Shank
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size	Drill Bit Point Type		Each
Jobbers' Length







				Uncoated

				4.0	0.1575"	79	41.9	Round	4 mm	Standard	28595A51	000000


				4.0	0.1575"	79	54	Round	4 mm	Split	28595A22	00000


				Short Length







								Uncoated

								4.0	0.1575"	52	12	Round	4 mm	Standard	28805A403	00000

Carbide Drill Bits for Carbon Fiber, Fiberglass, and Graphite

Jobbers' Length

Cut clean holes in abrasive material without fraying or delaminating the surface. Made of carbide, these bits resist wear to retain a sharp edge, even after after hundreds of cuts.

					Shank
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size, mm	Point Angle	Drill Bit Point Type	Bit Style		Each
Jobbers' Length







				Diamond Coated

				4.0	0.1575"	63	35	Round	4	140°	Brad	Fluted	3162A57	000000




						Uncoated

						4.0	0.1575"	63	35	Round	4	140°	Brad	Fluted	2828A117	00000

Carbide Drill Bits for Hardened Steel


Short Length Round Shank	Split

The hardest and most wear-resistant bits with the longest life. Straight flutes withstand the heavy pressure needed to penetrate hardened steel. These bits cut more aggressively and resist stress better than spiral-flute bits. Carbide stays sharp at high temperatures and faster speeds for the best performance on hard and difficult-to-machine materials. It can be brittle, however, so these bits require a rigid machine tool holder to prevent breakage and should not be used in hand drilling applications.

Short Length—The most rigid bits for drilling the straightest holes.

Uncoated—Excellent for a range of materials but won't last as long as coated bits.

					Shank
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size	Drill Bit Point Type		Each
Short Length







				Uncoated

				4.0	0.1575"	63	15.2	Round	4 mm	Split	8842A47	000000

Hole-Starting Cobalt Steel Drill Bits


120° Point Angle	Standard

Create an accurate starting place in your workpiece. Cut an indent with these bits, then continue drilling with a longer bit. The indent prevents slipping so the final hole is centered and precise. Cobalt steel resists wear to stay sharp when cutting hard materials, such as nickel. Also known as spotting drill bits.

Short Length—The most rigid bits for drilling the straightest holes.

Uncoated—Polished to eject chips, these are also known as bright finish bits.

					Shank			90° Point Angle		120° Point Angle
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size, mm	Drill Bit Point Type		Each		Each
Short Length







				Uncoated

				4.0	0.1575"	52	12.7	Round	4	Standard	27445A15	000000	27445A25	000000

Left-Hand High-Speed Steel Drill Bits


Jobbers' Length Round Shank	Standard

With flutes that spiral in the opposite direction of other bits, these are primarily used to remove stripped screws. Choose a bit that’s slightly smaller than the diameter of the screw’s head. Set your power tool to rotate in reverse. Slowly drill in the center of the screw head, maintaining constant pressure. As the bit penetrates, it will catch onto the screw and reverse it out of the hole. If the screw is badly stripped, you might need to punch a starter hole. Also known as reverse-flute bits. High-speed steel is the versatile choice for drilling most metals.

Jobbers' Length—These bits have the balance of rigidity and length needed for most applications.

Black Oxide—The dark finish increases wear resistance and reduces friction to improve chip flow, so these bits can last 50% longer than uncoated bits.

					Shank				Each
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size	Drill Bit Point Type		1-9	10-Up
Jobbers' Length







				Black Oxide

				4.0	0.1575"	75	35	Round	4 mm	Standard	29855A56	00000	00000

Smooth-Finish Carbide Drill Bits


Jobbers' Length Round Shank	Split

With more cutting edges than other drill bits, these cut continuously and consistently for a smoother finish. They also stay centered to produce holes that are straighter and more accurate. However, since there’s less space between the cutting edges, they don’t clear chips as quickly. Made of carbide, these are the hardest and most wear-resistant drill bits you can buy. They stay sharp at high temperatures and faster speeds for the best performance on hard and difficult-to-machine materials. Carbide can be brittle, however, so these bits require a rigid machine tool holder to prevent breakage and should not be used in hand drilling applications.

Jobbers' Length—These bits have the balance of rigidity and length needed for most applications.

Uncoated—Excellent for a range of materials but won't last as long as coated bits.

					Shank
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size	Drill Bit Point Type		Each
Jobbers' Length







				Uncoated

				4.0	0.1575"	55	21.9	Round	4 mm	Split	2783A2	000000

Chip-Clearing High-Speed Steel Drill Bits


Jobbers' Length High Helix Flute Round Shank	Jobbers' Length Parabolic Flute Round Shank	Split

With flutes that lift chips out of the hole, you don't have to stop drilling to clear these bits manually. They improve coolant flow to dissipate heat and prevent clogs that can damage the bit and ruin the hole. High-speed steel is good for general purpose drilling in most metals.

High Helix Flute—Less aggressive than parabolic flutes for cleaner cuts in soft metals.

Parabolic Flute—A U-shaped groove on the flutes cuts faster and clears chips more quickly than high-helix bits, so these are better for drilling deeper holes.

Jobbers' Length—These bits have the balance of rigidity and length needed for most applications.

Black Oxide—The dark finish increases wear resistance and reduces friction to improve chip flow, so these bits can last 50% longer than uncoated bits.

Titanium Nitride (TiN) Coated—Drill at higher speeds and last longer than uncoated and oxide-coated bits, especially on tough materials like hardened steel and nickel.

Uncoated—The most economical option, uncoated bits perform best when used on low-carbon steel and aluminum. Polished to reduce friction, they're also known as bright finish bits.

						Shank
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Flute Type	Type	Size, mm	Drill Bit Point Type		Each
Jobbers' Length







				Black Oxide

				4.0	0.1575"	75	35	High Helix	Round	4	Split	30055A59	00000




						Titanium Nitride (TiN) Coated

						4.0	0.1575"	75	43	Parabolic	Round	4	Split	7333N22	0000




								Uncoated

								4.0	0.1575"	75	35	Parabolic	Round	4	Split	2754A26	0000

Chip-Clearing Cobalt Steel Drill Bits

Jobbers' Length

Parabolic Flute

Round Shank

Split

Avoid clogs and dissipate heat with cobalt bits that last at least twice as long as high-speed steel. The flutes clear chips to improve coolant flow and prevent damage to the bit and the hole. They also speed up drilling since you don't have to stop to clear the bit manually.

Jobbers' Length—These bits have the balance of rigidity and length needed for most applications.

Uncoated—Polished to eject chips, these are also known as bright finish bits.

						Shank
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Flute Type	Type	Size, mm	Drill Bit Point Type		Each
Jobbers' Length







				Uncoated

				4.0	0.1575"	76	41	Parabolic	Round	4	Split	2771N49	00000

Carbide Drill Bits for Sheet Metal

Short Length

Round Shank

Standard

The hardest and most wear-resistant bits for sheet metal and thin-wall tubing. They have short flutes that make shallow cuts without snagging and deforming the material. Carbide stays sharp at high temperatures and faster speeds than high-speed steel. It can be brittle, however, so these bits require a rigid machine tool holder to prevent breakage and should not be used in hand drilling applications.

Short Length—The most rigid bits for drilling the straightest holes.

Uncoated—Excellent for a range of materials but won't last as long as coated bits.

					Shank
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size	Drill Bit Point Type	No. of Drilling Ends		Each
Short Length







				Uncoated

				4.0	0.1575"	50	8	Round	4 mm	Standard	1	8769A42	000000

Chip-Clearing Cobalt Steel Drill Bits for Nickel and Stainless Steel

Jobbers' Length

Parabolic Flute

Round Shank

Split

Excellent for challenging metals such as stainless steel and nickel alloys, these bits cut aggressively and evacuate chips quickly. The grooved flutes prevent clogs and improve coolant flow to dissipate heat that can damage the bit or your material. Bits are made of tough and wear-resistant cobalt steel.

Jobbers' Length—These bits have the balance of rigidity and length needed for most applications.

						Shank
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Flute Type	Type	Size, mm	Drill Bit Point Type		Each
Jobbers' Length







				Titanium Aluminum Nitride (TiAlN) Coated

				4.0	0.1575"	75	43	Parabolic	Round	4	Split	3020A43	000000

Depth-Limiting Drill Stops

Image of ProductInUse. Front orientation. Drill Stops.

Ensure identical hole depths every time. Position the collar on your bit and tighten the set screw.

	For Drill Bit Size Decimal Equiv.	Overall Lg.	OD	Hex Key Size for Set Screw	Material		Each
For Metric Drill Bits



	4.0 mm	0.1575"	1/2"	7/16"	3/32"	Steel	8865A145	00000