Hertel 42120 Cobalt Jobber Drill 3/64 in 135 Deg Split Point

Product Description

The HERTEL 42120 is a cobalt jobber-length drill bit designed for drilling into stainless steel, hardened materials, and other tough alloys that wear down standard high-speed steel tooling. Built to M35 grade cobalt steel, it carries a 135-degree split-point geometry that reduces walking and lowers the thrust needed to start a hole without a center punch. The bit measures 3/64 inch (0.0469 inch decimal) in diameter with a 3/4-inch flute length and 1-3/4-inch overall length. A regular spiral flute pattern clears chips efficiently in both hand-held and drill-press applications. Right-hand cutting only.

This bit is sized for precision work in light fabrication, maintenance, and repair environments where small-diameter holes are required in corrosion-resistant or hardened base materials. The heavy-duty grade construction makes it suitable for production drilling in stainless steel sheet, angle iron, and similar ferrous and non-ferrous alloys. It is sold individually but requires a minimum order of 12 units. HVAC techs, pipefitters, and maintenance mechanics reaching for a small-diameter cobalt bit for sheet metal or hardware drilling will find this a capable option at the 3/64-inch size.

Key Features

• M35 cobalt steel construction resists heat buildup when drilling stainless steel and hardened materials
• 135-degree split-point tip reduces drill walking and lowers required feed pressure
• Regular spiral flute promotes efficient chip evacuation in deep or repetitive holes
• Straight cylindrical shank fits standard drill chucks without adapters
• Right-hand cutting direction compatible with all standard drill presses and hand drills
• Heavy-duty grade designation rated for intermittent production use, not just occasional service

Compatibility

Designed as a general-purpose cobalt jobber drill bit for use in any standard drill chuck accepting a straight cylindrical shank at the 3/64-inch diameter. Primary workpiece materials include stainless steel and hardened metals.

Installation Notes

This drill bit is installed and used by machinists, pipefitters, HVAC technicians, and general maintenance trades. Secure the workpiece before drilling to prevent rotation or movement. Use appropriate cutting fluid or coolant when drilling stainless steel to extend bit life and reduce work hardening at the cut zone. Inspect the split point for chipping before each use; a damaged point will increase thrust requirements and reduce hole accuracy.