8.3 mm Drill Bits | McMaster-Carr

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
	Drill Bit Size, mm	Decimal Size Equiv.	Overall Lg., mm	Max. Drilling Dp., mm	Type	Size	Drill Bit Point Type		1-4	5-Up
Jobbers' Length







				Gold Oxide

				8.3	0.3268"	117	83.3	Round	8.3 mm	Split	30565A308	00000	00000

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		1-4	5-Up
Jobbers' Length







				Uncoated

				8.3	0.3268"	117	83.3	Round	8.3 mm	Split	29355A136	000000	000000

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

				8.3	0.3268"	117	73	Parabolic	Round	8.3	Split	2771N779	000000

Helical Threaded Inserts with Installation Tools

Drill Bit, Installation Tool

and Through-Hole Tap

Quickly restore stripped threads—these inserts come with through-hole taps and installation tools. The tough coils on these inserts expand once installed to anchor in a tapped hole.

Pronged—The prong attaches to an installation tool for precise control as you drive inserts in. Remove the prong with a punch or break-off tool before inserting a screw.

18-8 Stainless Steel—The choice for wet and outdoor environments, these inserts resist rust and mild chemicals.

	For Max. Hole Dia.	No. of Inserts Included	Includes		Each
Pronged







	18-8 Stainless Steel

	M8 x 1.25 mm	8	8.3	0.328"	10	Drill Bit Installation Tool Through-Hole Tap	91732A481	0000000


	M8 x 1.25 mm	12	8.3	0.328"	10	Drill Bit Installation Tool Through-Hole Tap	91732A952	00000
	M8 x 1.25 mm	16	8.3	0.328"	10	Drill Bit Installation Tool Through-Hole Tap	91732A491	000000
	M8 x 1.25 mm	20	8.3	0.328"	10	Drill Bit Installation Tool Through-Hole Tap	98356A161	00000
	M8 x 1.25 mm	24	8.3	0.328"	10	Drill Bit Installation Tool Through-Hole Tap	98356A162	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
8.3	-0.005 to 0	8.3	4 5/8"	Not Rated	Rockwell C60 (Extra Hard)	Precision Ground	2900A362	00000