52mm Long Drill Bits | McMaster-Carr

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.

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







				Black Oxide

				3.4	0.1339"	52	13.1	Round	3.4 mm	Split	28255A27	00000


				3.5	0.1378"	52	12.9	Round	3.5 mm	Split	28255A31	0000
				3.6	0.1417"	52	9	Round	3.6 mm	Split	28255A85	0000
				3.7	0.1457"	52	20	Round	3.7 mm	Split	28255A113	0000




						Titanium Nitride (TiN) Coated

						3.4	0.1339"	52	8.5	Round	3.4 mm	Split	2979N55	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		Each
Jobbers' Length







				Uncoated

				3.4	0.1339"	52	19.9	Round	3.4 mm	Split	2783A14	000000


				3.5	0.1378"	52	19.9	Round	3.5 mm	Split	2783A15	00000

Cobalt Steel Drill Bits


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.

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
Short Length







				Titanium Nitride (TiN) Coated

				3.5	0.1378"	52	13	Round	3.5 mm	Split	2456N147	00000




						Uncoated

						3.5	0.1378"	52	13	Round	3.5 mm	Split	2456N119	0000

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

Carbide-Tipped Drill Bits

Short 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.

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
Short Length







				Uncoated

				3.5	0.1378"	52	10.5	Round	3.5 mm	Standard	28805A402	000000


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

Cubic Boron Nitride Ball End Mills for Tool Steel and Hardened Steel


Ball Cut Style

Make finishing cuts in tool steel and hardened steel with these cubic boron nitride (CBN) end mills. Harder than carbide end mills, they’re better for making small, precise cuts and last more than five times as long. And while they’re not as hard as diamond end mills, they dissipate heat much better. These end mills have a 0° helix angle for increased rigidity, helping to prevent chipping and ensuring more precise cuts. Deep chip pockets remove small chips for greater precision and to prevent surface roughening.

Because they’re brittle, these end mills require a highly rigid setup such as a CNC machine to prevent them from breaking. It’s also recommended that they’re used with oil coolant.

Mill, mm			Neck, mm									For Maximum Hardness Rockwell C70
Dia.	Dia. Tolerance	Shank Dia., mm	Dia.	Lg.	Lg. of Cut, mm	Overall Lg., mm	Flute Spacing	Helix Angle	For Use On	End Mill Type	Cut Style		Each







			2 Flutes

			1.5	-0.006 to 0.006	4	1.45	2.8	1	52	Equal	0°	Hardened Steel, Tool Steel	Center Cutting	Ball	7977N24	0000000


			2	-0.006 to 0.006	4	1.94	3.8	1.2	52	Equal	0°	Hardened Steel, Tool Steel	Center Cutting	Ball	7977N26	000000