3/4 Drill Bits for Hardened Steel

A 3/4-inch M35 cobalt jobber drill bit with a 135-degree split point is ideal for steel, including stainless and hardened grades. The cobalt content provides heat resistance during high-speed drilling, while the fractional sizing ensures compatibility with standard chucks used in machine shops and fabrication work.

Cobalt bits (M35 grade) contain cobalt alloy for superior heat resistance and hardness, making them better suited for stainless steel and hardened metals. Black & gold bits use oxide-coated high-speed steel, offering solid performance for general-purpose drilling in softer metals, wood, and plastic at a more economical price point.

A 135-degree split point reduces bit walking by self-centering on contact, eliminating the need for a center punch in most applications. It also distributes cutting pressure more evenly across the tip, resulting in faster starts, cleaner holes, and reduced heat buildup during metal drilling operations.

Yes, the M35 cobalt jobber drill bits are specifically formulated for stainless steel and other hard metals. Cobalt's heat resistance allows the bit to maintain its cutting edge even under the friction generated when drilling dense, work-hardening materials like stainless steel.

Fractional drill bits are sized in standard increments such as 1/16, 1/8, 1/4, 1/2, and 3/4 inch, among others, making them compatible with common chucks and measurement systems used in US machine shops. This category focuses on 3/4-inch bits suited for larger diameter holes in hardened steel.

Jobber length bits offer a versatile middle ground between short and extra-long bits, suitable for most general-purpose and industrial drilling tasks. They provide enough reach for standard hole depths while maintaining rigidity, making them a practical default choice for shops drilling hardened steel and other metals.