4.2mm Shank Size Drill Bits

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.

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.

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







				Black Oxide

				4.2	0.1654"	75	34.6	Round	4.2 mm	Standard	Dormer Pramet	2958A74	00000	10	2958A742	000000




						Titanium Nitride (TiN) Coated

						4.2	0.1654"	75	36.7	Round	4.2 mm	Standard	Chicago-Latrobe	8950A16	0000	—	———	0




								Black/Gold Oxide

								4.2	0.1654"	83	49.2	Round	4.2 mm	Split	Viking Norseman Drill	30565A263	0000	10	30565A43	00000


								Short Length







												Black Oxide

												4.2	0.1654"	55	13.5	Round	4.2 mm	Split	Dormer Pramet	28255A35	0000	—	———	0




														Titanium Nitride (TiN) Coated

														4.2	0.1654"	56	22.1	Round	4.2 mm	Split	Dormer Pramet	2979N2	0000	—	———	0


														Extended Length







																		Black Oxide

																		4.2	0.1654"	119	78	Round	4.2 mm	Standard	Dormer Pramet	88455A118	00000	—	———	0




																				Uncoated

																				4.2	0.1654"	119	69.3	Round	4.2 mm	Standard	Dormer Pramet	3083A146	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.

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—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	Mfr.		Each
Jobbers' Length







				Titanium Nitride (TiN) Coated

				4.2	0.1654"	75	42.9	Round	4.2 mm	Split	Dormer Pramet	5058N62	00000




						Titanium Aluminum Nitride (TiAlN) Coated

						4.2	0.1654"	75	36.7	Round	4.2 mm	Split	Guhring	2753A168	00000




								Gold Oxide

								4.2	0.1654"	75	34.6	Round	4.2 mm	Split	Dormer Pramet	29355A66	0000


								Short Length







												Titanium Nitride (TiN) Coated

												4.2	0.1654"	56	13.7	Round	4.2 mm	Split	Chicago-Latrobe	2456N149	0000




														Uncoated

														4.2	0.1654"	56	13.7	Round	4.2 mm	Split	Chicago-Latrobe	2456N122	0000

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	Mfr.		Each
Jobbers' Length







				Uncoated

				4.2	0.1654"	55	21.9	Round	4.2 mm	Split	Kyocera	2783A22	000000

Carbide-Tipped Drill Bits

Jobbers' 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.

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







				Uncoated

				4.2	0.1654"	89	47	Round	4.2 mm	Standard	Izar	28595A53	000000


				4.2	0.1654"	89	54	Round	4.2 mm	Split	ICS	28595A23	00000

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	Mfr.		Each
Jobbers' Length







				Uncoated

				4.2	0.1654"	76	41	Parabolic	Round	4.2	Split	Viking Norseman Drill	2771N51	00000

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	Mfr.		Each
Jobbers' Length







				Titanium Aluminum Nitride (TiAlN) Coated

				4.2	0.1654"	75	43	Parabolic	Round	4.2	Split	Guhring	3020A44	000000

Chip-Clearing High-Speed Steel Drill Bits

Jobbers' Length

High Helix 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.

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







				Black Oxide

				4.2	0.1654"	75	34.6	High Helix	Round	4.2	Split	Dormer Pramet	30055A61	00000

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	Mfr.		1-9	10-Up
Jobbers' Length







				Black Oxide

				4.2	0.1654"	75	34.6	Round	4.2 mm	Standard	Dormer Pramet	29855A57	000000	000000