4.5 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

				4.5	0.1772"	80	38	Round	4.5 mm	Standard	2958A77	00000	—	———	0




						Titanium Nitride (TiN) Coated

						4.5	0.1772"	80	38	Round	4.5 mm	Standard	8950A53	0000	—	———	0




								Gold Oxide

								4.5	0.1772"	86	50.8	Round	4.5 mm	Split	30565A266	0000	10	30565A432	000000




										Uncoated

										4.5	0.1772"	86	46.8	Round	4.5 mm	Standard	2951A133	0000	—	———	0


										Short Length







														Black Oxide

														4.5	0.1772"	58	14.9	Round	4.5 mm	Split	28255A37	0000	—	———	0




																Titanium Nitride (TiN) Coated

																4.5	0.1772"	57	23.9	Round	4.5 mm	Split	2979N21	0000	—	———	0


																Extended Length







																				Uncoated

																				4.5	0.1772"	126	72.7	Round	4.5 mm	Standard	3083A149	0000	—	———	0

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.

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, titanium, and fiberglass.

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

				4.5	0.1772"	79	47	Round	4.5 mm	Split	5058N63	00000




						Titanium Aluminum Nitride (TiAlN) Coated

						4.5	0.1772"	80	40.3	Round	4.5 mm	Split	2753A169	00000




								Gold Oxide

								4.5	0.1772"	80	38	Round	4.5 mm	Split	29355A71	0000


								Short Length







												Titanium Nitride (TiN) Coated

												4.5	0.1772"	59	15	Round	4.5 mm	Split	2456N151	0000




														Uncoated

														4.5	0.1772"	59	15	Round	4.5 mm	Split	2456N123	0000

Drill Bit Guides

Place these guides on your workpiece to drill precise holes without building a fixture. They'll even work on corners and round surfaces. Lines marked on the side allow you to align your holes accurately. Made of hardened steel, they’re tough enough to withstand frequent use.

For Drill Bit Size, mm	For Drill Bit Size Decimal Equiv.	Lg.	Wd.	Ht.	Material		Each
3, 3.3, 3.5, 4, 4.2, 4.5, 5, 5.5, 6, 6.5, 6.8, 7, 7.5, 8, 8.5, 9, 9.5	0.1181", 0.1299", 0.1378", 0.1575", 0.1654", 0.1772", 0.1968", 0.2165", 0.2362", 0.2559", 0.2677", 0.2756", 0.2953", 0.315", 0.3346", 0.3543", 0.374"	5 1/2"	3/4"	7/8"	Steel	9550T15	000000

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

				4.5	0.1772"	70	41	Round	4.5 mm	Four Facet	3030A79	000000




						Uncoated

						4.5	0.1772"	70	32.8	Round	4.5 mm	Four Facet	3030A28	00000


						Short Length
						Round Shank






										Titanium Nitride (TiN) Coated

										4.5	0.1772"	63	19	Round	4.5 mm	Four Facet	27515A714	00000




												Titanium Aluminum Nitride (TiAlN) Coated

												4.5	0.1772"	63	19	Round	4.5 mm	Four Facet	8879A614	00000




														Uncoated

														4.5	0.1772"	63	19	Round	4.5 mm	Four Facet	2956A814	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

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

				4.5	0.1772"	89	47	Round	4.5 mm	Standard	28595A56	000000


				4.5	0.1772"	89	56	Round	4.5 mm	Split	28595A24	00000


				Short Length







								Uncoated

								4.5	0.1772"	56	13.5	Round	4.5 mm	Standard	28805A404	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

				4.5	0.1772"	70	41	Round	4.5	140°	Brad	Fluted	3162A58	000000




						Uncoated

						4.5	0.1772"	70	41	Round	4.5	140°	Brad	Fluted	2828A118	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



		4.5	0.1772"	80	55	Round	4.5	60°	Standard	27465A414	00000

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

				4.5	0.1772"	86	56	Round	4.5 mm	Split	3474A55	000000	000000

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

				4.5	0.1772"	79	45	Parabolic	Round	4.5	Split	2771N52	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

				4.5	0.1772"	63	15.2	Round	4.5 mm	Split	8842A48	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.

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

				4.5	0.1772"	80	38	High Helix	Round	4.5	Split	30055A62	00000




						Uncoated

						4.5	0.1772"	80	38	Parabolic	Round	4.5	Split	2754A27	0000

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

				4.5	0.1772"	80	38	Round	4.5 mm	Standard	29855A58	000000	000000

Undersized Hardened Multipurpose M2 High-Speed Tool Steel Rods

These rods, also known as drill blanks, have an undersized diameter for machining your own drill bits. They're hardened for increased abrasion and impact resistance. M2 tool steel offers a nice balance of wear resistance and machinability. It has a high molybdenum content, which allows it to maintain sharp cutting edges even at elevated temperatures.

Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.

Dia., mm	Dia. Tolerance, mm	Drill Bit Size, mm	Lg.	Yield Strength	Hardness	Mechanical Finish		Each
4.5	-0.005 to 0	4.5	3 3/8"	Not Rated	Rockwell C60 (Extra Hard)	Precision Ground	2900A289	00000

Tight-Tolerance Water-Hardening W1 Tool Steel Rods

Ready for turning in your lathe, these rods are precision ground and held to strict diameter and straightness tolerances. Also known as drill rod. With far less alloy content than other tool steel, W1 is the most machinable we offer. These rods are often used to make hammers, files, and reamers—tools that don't require the dimensional stability of A2 or O1. These rods are also decarb-free, which means any surface flaws created during the manufacturing process have been removed. This makes them even more machinable and leads to better results from heat treating or finishing. Heat treat the surface for extra wear resistance. Or, quench this steel in water to boost its hardness and strength, giving it a sharper, more durable edge for small tools.

Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.

Dia.	Dia. Tolerance	Drill Bit Size, mm	Fabrication	Heat Treatment	Yield Strength, psi	Mechanical Finish	Hardness	Max. Hardness After Heat Treatment	Specs. Met		3 ft. Long	6 ft. Long
0.178"	-0.001" to 0.001"	4.5	Hot Rolled	Annealed	50,000	Precision Ground	Rockwell B95 (Medium)	Rockwell C65	ASTM A686	8890K172	00000	00000