Hertel 42007 Cobalt Jobber Drill Bit 21/64 in 135 Deg

Product Description

The HERTEL 42007 is a cobalt jobber length drill bit designed for drilling through hard and abrasive materials including stainless steel, high-strength alloys, and hardened steels. The bit measures 21/64 inches (0.3281 inches) in diameter with a 4-5/8 inch overall length and a 3-5/16 inch flute length. The 135-degree split point reduces walking on entry without a center punch and requires less feed pressure than a standard 118-degree point. An oxide and gold coating provides additional surface hardness and lubricity. This bit is suited for machine shop, maintenance, and fabrication work performed by machinists, pipefitters, and general trade mechanics.

The HERTEL 42007 fits standard drill chucks and is appropriate for use in bench drill presses, magnetic base drills, and hand-held power drills running at appropriate speeds for cobalt tooling. The straight cylindrical shank seats cleanly in three-jaw chucks. The 5xD flute-to-diameter ratio and regular spiral geometry support consistent chip evacuation in most ferrous and non-ferrous materials. This bit is sold individually and is a practical replacement for worn or broken jobber bits in the 21/64 inch size class.

Key Features

• 21/64 inch diameter (0.3281 inches decimal) cobalt construction for heat resistance in tough materials
• 135-degree split point reduces thrust force and eliminates center-punch requirement on most surfaces
• Oxide and gold coating increases surface lubricity and wear resistance
• Right-hand spiral flute with regular helix promotes consistent chip clearing
• Straight cylindrical shank compatible with standard three-jaw drill chucks
• 4-5/8 inch overall length fits most production and maintenance drilling setups

Compatibility

Designed as a standard jobber length drill bit for use in any drill press, magnetic drill, or hand-held power tool with a chuck capacity that accommodates a straight cylindrical shank in the 21/64 inch size range.

Installation Notes

Install and remove drill bits only when the machine is powered off and the spindle has come to a complete stop. Secure the shank fully in the chuck and verify concentricity before running. Use cutting fluid appropriate for cobalt tooling when drilling ferrous metals to extend tool life and manage heat. Dispose of worn or chipped bits in a sharps-safe container per shop safety protocols.