Jacobs 8 1/2N Drill Chucks

Secure bits into your drill press, milling machine, or lathe. These chucks are keyed, so they grip bits tightly to prevent slipping under heavy loads. Use the included key to tighten and loosen the jaws. Attach these chucks to your machine with a Jacobs taper arbor. To maximize grip and minimize runout, choose a chuck where your drill bit diameter falls in the middle of the bit shank size range.

Jacobs—Jacobs chucks are the most widely used drill chucks.

Ball Bearing—Chucks with ball bearings produce less friction for the best grip on bits. Use them for tight tolerance drilling to make accurate holes. They’re also known as super chucks.

Heavy Duty—Heavy duty chucks give you the rigidity and heft needed for high-torque drilling in hardened metal. Their extra mass means they resist vibration and fluctuating cutting forces to keep your bit stable. While they share all of the same features as medium duty chucks—one-piece sleeve, center-ground jaws, and hardened wear points—they grip bits tighter and stay accurate longer under heavy loads.

	Drill Chucks														Service Kits
						Chuck Key
	Machine Taper No.	For Bit Shank Size	Duty Rating	Wt., lb.	Total Indicated Runout (TIR) Accuracy	Included	No.	Jaw Material	Body Material	For Use With	For Tool Drive Direction	Mfr. Model No.		Each		Each
Jacobs—Ball Bearing



		Jacobs 2	0.04" to 1/4" 1 mm to 6.5 mm	Heavy	0.7	0.003"	Yes	K30	Steel	Steel	Drill Presses Lathes Milling Machines	Clockwise, Counterclockwise	8 1/2N	2815A11	0000000	2815A41	0000000