Hertel 04138897 Cobalt Jobber Drill No 42 135 Deg

Product Description

The HERTEL 04138897 is a cobalt jobber-length drill bit sized to wire gauge No. 42 (0.0935 inches decimal), designed for heavy-duty holemaking in ferrous metals, stainless steel, and other hard materials that would quickly wear out standard high-speed steel tooling. The 135-degree split point self-centers on the workpiece and reduces the thrust required to start the cut, making it well suited for production drilling without a center punch. An oxide and TiN coating protects the cutting edges and helps evacuate chips through the spiral flute. The straight cylindrical shank (0.0935 inches) fits standard drill chucks without adapters.

This drill bit is used in metalworking, fabrication, HVAC sheet-metal work, plumbing rough-in, and electrical trade applications where small-diameter, precise holes are required in tough base materials. The jobber-length body (2.25 inches overall, 1.25-inch flute length) provides a practical balance of reach and rigidity for bench drill press, hand drill, and right-angle drill applications. The regular spiral and tapered web configuration help maintain chip flow in deep cuts relative to the bit diameter.

Key Features

• Cobalt construction for heat resistance in hard and abrasive metals
• 135-degree split point self-centers and lowers drilling thrust
• Oxide and TiN dual coating for extended edge life
• Web-thinned, tapered web for improved chip evacuation
• Right-hand spiral flute, regular helix for standard drill press and hand-drill use
• Heavy-duty grade rated for continuous production holemaking

Compatibility

Designed as a jobber-series replacement drill bit for any standard drill chuck accepting a 0.0935-inch straight cylindrical shank, suitable for wire-gauge No. 42 holemaking applications across metalworking and trade use.

Installation Notes

Secure the shank fully in the drill chuck before applying power and verify chuck key is removed. Use cutting fluid or coolant when drilling stainless or hardened alloys to extend bit life, even though this bit does not support through-coolant delivery. Inspect the cutting edges before each use; cobalt bits can chip if run at excessively high feed rates in interrupted cuts. Discard bits with visible chipping rather than regrinding without proper equipment.