6.6 mm 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.

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

				6.6	0.2598"	101	49.8	Round	6.6 mm	Standard	2958A112	00000




						Gold Oxide

						6.6	0.2598"	105	69.9	Round	6.6 mm	Split	30565A289	0000


						Short Length







										Black Oxide

										6.6	0.2598"	70	31	Round	6.6 mm	Split	28255A118	0000

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.

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.

					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

				6.6	0.2598"	101	63	Round	6.6 mm	Split	5058N35	000000




						Titanium Aluminum Nitride (TiAlN) Coated

						6.6	0.2598"	101	63	Round	6.6 mm	Split	2753A237	00000




								Gold Oxide

								6.6	0.2598"	101	49.8	Round	6.6 mm	Split	29355A112	0000

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

				6.6	0.2598"	101	61	Parabolic	Round	6.6	Split	2771N767	00000

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
6.6	-0.005 to 0	6.6	4 1/8"	Not Rated	Rockwell C60 (Extra Hard)	Precision Ground	2900A343	00000