8.3 mm Drill Bits | McMaster-Carr

				Shank					Each
Drill Bit Size	Decimal Size Equivalent	Overall Lg.	Max. Drilling Dp.	Type	Size	Point Style	Specifications Met	For Use On		Each
Metric
Black-and-Gold Oxide High-Speed Steel
8.3 mm	0.3268"	117mm	83.3mm	Round	8.3mm	Split	NAS907 Type B	Steel, Iron, Stainless Steel	000000000	00000

Cobalt Steel Drill Bits

Uncoated

These jobbers'-length bits have the rigidity and length required for most applications. Made of cobalt steel, which has better heat and wear resistance than high-speed steel, they can run up to 25% faster and have a longer tool life.

Drill bits with a split point keep centered without a pilot hole.

For technical drawings and 3-D models, click on a part number.

				Shank					Each
Drill Bit Size	Decimal Size Equivalent	Overall Lg.	Max. Drilling Dp.	Type	Size	Point Style	Specifications Met	For Use On		Each
Metric
Uncoated Cobalt Steel
8.3 mm	0.3268"	117mm	83.3mm	Round	8.3mm	Split	NAS907 Type J	Steel, Hardened Steel, Tool Steel, Iron, Stainless Steel, Nickel	000000000	000000

Chip-Clearing Cobalt Steel Drill Bits

Uncoated

The parabolic spiral flutes lift chips out of the hole, reducing clogging and improving coolant flow. With better heat and wear resistance than high-speed steel, these cobalt steel bits can run up to 25% faster and have a longer tool life. All are jobbers’ length so they have the rigidity and length required for most applications. A split point keeps the bit centered without a pilot hole.

For technical drawings and 3-D models, click on a part number.

				Shank
Drill Bit Size	Decimal Size Equivalent	Overall Lg.	Max. Drilling Dp.	Type	Size	Point Style	Specifications Met	For Use On		Each
Metric—Parabolic Spiral Flute
Uncoated Cobalt Steel
8.3 mm	0.3268"	117mm	75mm	Round	8.3mm	Split	DIN 338	Steel, Hardened Steel, Tool Steel, Iron, Stainless Steel, Nickel	00000000	000000

Hardened Undersized High-Speed M2 Tool Steel Rods

Yield Strength: Not Rated
Hardness: Rockwell C60 (Very Hard)

These rods, also known as drill blanks, have an undersized diameter for machining your own jobbers'-length 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.

For technical drawings and 3-D models, click on a part number.

Certificates with a traceable lot number are available for these products. Download certificates from ORDER HISTORY after your order ships.

Dia.	Dia. Tolerance	Drill Bit Size	Lg.	Mechanical Finish	Straightness Tolerance		Each
8.3mm	-0.0050mm to 0.0000mm	8.3 mm	4 5/8"	Precision Ground	0.012" per ft.	00000000	00000

Helical Inserts with Installation Tools

Shown with Five Inserts and Drill Bit

Inserts come with a through-hole tap and installation tool. Also known as Heli-Coil inserts, they have coils that expand once installed to securely anchor the insert. All have a prong for ease of installation. An installation tool grips the prong and reduces the coil diameter, enabling the insert to fit in tapped holes. Remove the prong to insert the screw.

Metric

18-8 Stainless Steel—Right-Hand Threaded
Thread Size	Thread Pitch, mm	Thread Spacing	Installed Lg., mm	Drill Bit Size	For Max. Hole Dia.	No. of Inserts Included	Includes		Each
M8	1.25	Coarse	8	8.3 mm	21/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	0000000
M8	1.25	Coarse	12	8.3 mm	21/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
M8	1.25	Coarse	16	8.3 mm	21/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	000000
M8	1.25	Coarse	20	8.3 mm	21/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000
M8	1.25	Coarse	24	8.3 mm	21/64"	10	Drill Bit, Through-Hole Tap, Installation Tool	000000000	00000