121mm Long Drill Bits | McMaster-Carr

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.

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	Mfr.		Each	Pkg. Qty.		Pkg.
Jobbers' Length







				Black/Gold Oxide

				8.4	0.3307"	121	86.1	Round	8.4 mm	Split	Viking Norseman Drill	30565A309	00000	—	———	0


				8.5	0.3346"	121	86.1	Round	8.5 mm	Split	Viking Norseman Drill	30565A311	0000	5	30565A444	000000
				8.6	0.3386"	121	86.1	Round	8.6 mm	Split	Viking Norseman Drill	30565A312	0000	—	———	0
				8.7	0.3425"	121	86.1	Round	8.7 mm	Split	Viking Norseman Drill	30565A313	0000	—	———	0




						Uncoated

						8.5	0.3346"	121	74.6	Round	8.5 mm	Standard	Viking Norseman Drill	2951A142	0000	—	———	0

Cobalt Steel Drill Bits


Jobbers' 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.

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	Mfr.		1-4	5-Up
Jobbers' Length







				Uncoated

				8.6	0.3386"	121	86.1	Round	8.6 mm	Split	Viking Norseman Drill	29355A139	000000	000000


				8.7	0.3425"	121	60.7	Round	8.7 mm	Split	Viking Norseman Drill	29355A141	00000	00000

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

				8.5	0.3346"	121	71.1	Round	8.5 mm	Standard	Izar	28595A74	000000


				8.5	0.3346"	121	85	Round	8.5 mm	Split	ICS	28595A33	00000

Carbide-Tipped Drill Bits for Hardened Steel

Jobbers' Length

Round Shank

Straight flutes withstand the heavy pressure needed to penetrate hardened steel. These bits cut more aggressively and resist stress better than spiral-flute bits. A lower-priced alternative to solid carbide, they stay sharp when drilling abrasive material but won’t last as long.

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

				8.5	0.3346"	121	34	Round	8.5 mm	Notched	Izar	2973A69	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	Mfr.		1-4	5-Up
Jobbers' Length







				Uncoated

				8.5	0.3346"	121	87	Round	8.5 mm	Split	Viking Norseman Drill	3474A64	000000	000000

Fast-Cut Roughing Carbide Square End Mills with Chamfer Corner

Serrations along the cutting edge act as chip breakers, so these end mills can remove large amounts of material at high speeds without sacrificing tool life. Variable spacing between the flutes reduces vibration, also allowing these end mills to provide fast cuts. A 45° corner chamfer improves cutting edge strength, so these end mills last longer than standard square end mills when milling hard material; however they do not create as sharp of a corner. With a high helix angle and wear-resistant titanium aluminum nitride (TiAlN) or aluminum titanium nitride (AlTiN) coating, these end mills provide excellent shearing and chip removal in stainless steel and titanium. They have a square end for milling square-bottomed slots, pockets, and edges. All are center cutting, allowing plunge cuts into a surface.

Made of solid carbide, these end mills are harder, stronger, and more wear resistant than high-speed steel and cobalt steel for the longest life and best finish on hard material. Their extreme hardness means they are brittle, so a highly rigid setup, such as a CNC machine, is necessary to prevent the end mill from breaking.

	Mill, mm
	Dia.	Dia. Tolerance	Shank Dia., mm	Lg. of Cut, mm	Overall Lg., mm	Flute Pitch	Chamfer Wd., mm	Corner Cutting Angle	Flute Spacing	Helix Angle	For Use On	End Mill Type	Cut Style		Each
Aluminum Titanium Nitride (AlTiN)-Coated Carbide







				4 Flutes

				25	-0.084 to 0.000	25	45	121	Coarse	0.8	45°	Variable	36° to 38°	Iron, Stainless Steel, Steel, Titanium	Center Cutting	Square	8207A115	0000000

Fast-Cut Carbide Square End Mills with Chamfer Corner


4 Flutes	End Mill with Coolant Holes

A 45° corner chamfer improves cutting edge strength, so these end mills last longer than standard square end mills when milling hard material; however they do not create as sharp of a corner. Variable spacing between the flutes reduces vibration, allowing these end mills to provide fast cuts, smooth finishes, and long tool life on hard materials. They have a square end for milling square-bottomed slots, pockets, and edges. All are center cutting, allowing plunge cuts into a surface.

End mills with fewer flutes provide better chip clearance for high-volume, high-speed plunge, slotting, and roughing cuts; end mills with more flutes provide a finer finish and operate with less vibration when run at high speeds.

End Mills for Coolant Holes—End mills with coolant holes allow coolant to run through the tool and directly to the cutting edge to help flush out chips. Use them in CNC machines with coolant-through technology.

Aluminum Titanium Nitride (AlTiN)-Coated Carbide—Titanium aluminum nitride (TiAlN)- and aluminum titanium nitride (AlTiN)-coated end mills dissipate heat better than other end mills, especially at high speeds. At high temperatures, the coating creates a layer of aluminum oxide that transfers heat to the chips, keeping the tool cool, even when used without lubrication.

Titanium Aluminum Silicon Nitride (TiAlSiN)-Coated Carbide—Titanium aluminum silicon nitride (TiAlSiN)-coated end mills are extremely resistant to wear and diffusion because they have especially high hardness, even at high temperatures.

	Overall Lg., mm	Chamfer Wd., mm	Corner Cutting Angle	Flute Spacing	Helix Angle	No. of Coolant Holes	For Use On	End Mill Type		Each
End Mills







	Aluminum Titanium Nitride (AlTiN)-Coated Carbide—4 Flutes

	25	25	45	121	0.5	45°	Variable	38°	—	Hardened Steel, Iron, Nickel, Stainless Steel, Steel, Titanium, Tool Steel	Center Cutting	8745A129	0000000


	End Mills for Coolant Holes







					Titanium Aluminum Silicon Nitride (TiAlSiN)-Coated Carbide—4 Flutes

					25	25	45	121	0.25	45°	Variable	36° to 38°	4	Iron, Nickel, Stainless Steel, Steel, Titanium	Center Cutting	8745A392	000000

Fast-Cut Carbide Rounded-Edge Square End Mills

Rounded-Edge-Square

Cut Style

4 Flutes

5 Flutes


Ramping Cut Shown	End Mill with Coolant Hole

Variable spacing between the flutes reduces vibration, allowing these end mills to provide fast cuts, smooth finishes, and long tool life on hard materials. Often used for slotting and pocketing cuts in mold and die making, these end mills have a 90° profile and rounded corners, which reduce flute breakage and chipping. Also known as corner radius end mills.

A titanium aluminum nitride (TiAlN) or aluminum titanium nitride (AlTiN) coating allows them to dissipate heat better than other end mills, especially at high speeds. At high temperatures, the coating creates a layer of aluminum oxide that transfers heat to the chips, keeping the tool cool, even when used without lubrication. This makes these good for aggressive machining while roughing or making interrupted cuts.

End Mills for Extreme Ramping and Plunging—End mills for extreme ramping and plunging are good for both angled and vertical cutting. Choose these end mills so you can have one tool for ramping and plunging. They can enter the material at up to a 45° ramping angle to reach your desired depth faster than standard end mills, which typically machine at 1° to 3° angles. These end mills also evacuate chips faster and last longer.

Center Cutting—Center-cutting end mills allow plunge cuts into a surface.

Noncenter Cutting—Noncenter-cutting end mills are for operations where the peripheral teeth do most of the work, such as shoulder milling, contouring, and finishing. They cannot be used for plunge cuts.

	Corner Cut Radius, mm	Overall Lg., mm	Flute Spacing	Helix Angle	Max. Ramping Angle	No. of Coolant Holes	For Use On	End Mill Type	Cut Style		Each
End Mills for Extreme Ramping and Plunging







	Aluminum Titanium Nitride (AlTiN)-Coated Carbide—4 Flutes

	25	25	50	1.5	121	Variable	37° to 39°	45°	—	Hardened Steel, Iron, Stainless Steel, Steel, Titanium, Tool Steel	Center Cutting	Rounded-Edge Square	6646N255	0000000


	25	25	50	3	121	Variable	37° to 39°	45°	—	Hardened Steel, Iron, Stainless Steel, Steel, Titanium, Tool Steel	Center Cutting	Rounded-Edge Square	6646N256	000000


	End Mills for Coolant Holes







					Aluminum Titanium Nitride (AlTiN)-Coated Carbide—5 Flutes

					25	25	53	1	121	Variable	37°	7°	1	Hardened Steel, Iron, Stainless Steel, Steel, Titanium, Tool Steel	Noncenter Cutting	Rounded-Edge Square	6646N203	000000


					25	25	53	2	121	Variable	37°	7°	1	Hardened Steel, Iron, Stainless Steel, Steel, Titanium, Tool Steel	Noncenter Cutting	Rounded-Edge Square	6646N202	000000
					25	25	53	2.5	121	Variable	37°	7°	1	Hardened Steel, Iron, Stainless Steel, Steel, Titanium, Tool Steel	Noncenter Cutting	Rounded-Edge Square	6646N204	000000
					25	25	53	3	121	Variable	37°	7°	1	Hardened Steel, Iron, Stainless Steel, Steel, Titanium, Tool Steel	Noncenter Cutting	Rounded-Edge Square	6646N201	000000
					25	25	53	4	121	Variable	37°	7°	1	Hardened Steel, Iron, Stainless Steel, Steel, Titanium, Tool Steel	Noncenter Cutting	Rounded-Edge Square	6646N205	000000
					25	25	53	5	121	Variable	37°	7°	1	Hardened Steel, Iron, Stainless Steel, Steel, Titanium, Tool Steel	Noncenter Cutting	Rounded-Edge Square	6646N206	000000