18.0 mm Drill Bits | McMaster-Carr

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, 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	000000
			6.0, 8.0, 10.0, 12.0, 14.0, 16.0, 18.0, 20.0, 22.0, 24.0, 26.0, 28.0, 30.0, 32.0	0.2362", 0.315", 0.3937", 0.4724", 0.5512", 0.6299", 0.7087", 0.7874", 0.8661", 0.9449", 1.0236", 1.1024", 1.1811", 1.2598", 1.378"	89	Round/3-Flat	9.53 mm	Standard	5910N22	000000



					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	1/4"	Standard	89275A36	00000



							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
							6.0, 8.0, 10.0, 12.0, 14.0, 16.0, 18.0	0.2362", 0.315", 0.3937", 0.4724", 0.5512", 0.6299", 0.7087"	64	Hex	10 mm	Standard	89275A13	00000

Reduced-Shank High-Speed Steel Drill Bits

Jobbers' Length


Standard	Split

Cut large holes with drill presses and portable drills that have a standard-size chuck. The shank on these bits has a smaller diameter than the cutting tip. High-speed steel is good for general purpose drilling in most metals. Also known as Silver and Deming bits.

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.

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.

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





				Black Oxide
				18.0	0.7087"	152	53.3	Reduced Round	1/2"	Standard	3091A39	000000



						Gold Oxide
						18.0	0.7087"	152	63.5	Reduced Round/3-Flat	1/2"	Split	6154N22	00000

High-Speed Steel Drill Bits

Jobbers' Length

Morse Taper Shank

Extended Length

Round Shank

Standard

Our basic drill bits are also the most versatile. Cut holes in a variety of metals, from the softest aluminum to the hardest steel.

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

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.

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





				Black Oxide
				18.0	0.7087"	228	93.9	Morse Taper	Morse 2	Standard	3070A168	0000000

				Extended Length





								Black Oxide
								18.0	0.7087"	241	158	Round	18 mm	Standard	88455A137	00000

Carbide-Tipped Drill Bits

Extended Length

Round Shank

Standard

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.

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





				Uncoated
				18.0	0.7087"	241	115	Round	18 mm	Standard	29465A127	0000000

Reduced-Shank Cobalt Steel Drill Bits

Jobbers' Length

Split

More wear resistant than high-speed steel, these bits cut large holes with tools that have a standard-size chuck. The shank has a smaller diameter than the cutting tip and fits drill presses and portable drills. 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. Also known as Silver and Deming 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
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size	Drill Bit Point Type		Each
Jobbers' Length





				Uncoated
				18.0	0.7087"	152	58	Reduced Round	1/2"	Split	8939A612	000000