Hertel 42281 Cobalt Jobber Drill Bit 7.50 Mm 135 Deg

Product Description

The HERTEL 42281 is a cobalt jobber-length drill bit designed for drilling into stainless steel, hardened materials, and other tough alloys that wear out standard high-speed steel tooling. Built from M35 cobalt steel, the bit features a 135-degree split point that reduces walking and cutting pressure at entry, making it well suited for controlled, repeatable hole-making in demanding shop and field environments. The overall length is 4.29 inches with a flute length of 2.72 inches. The straight cylindrical shank is compatible with standard drill chucks. This bit is sold individually and is intended for use by machinists, maintenance technicians, pipefitters, and fabricators who regularly work with corrosion-resistant or high-alloy materials.

This drill bit is sized at 7.50 mm (0.2953 inches) and falls within the 7.00 to 8.00 mm diameter range. It is appropriate for use in hand-held drill motors, drill presses, and magnetic base drills in both shop and on-site fabrication settings. Typical applications include drilling pilot or through holes in stainless steel pipe, plate, structural members, and hardened fastener seats. The right-hand spiral flute and regular spiral geometry support efficient chip evacuation during through-hole operations. No coolant-through capability is present, so external cutting fluid or paste is recommended when drilling deep holes in hard materials.

Key Features

• M35 cobalt steel construction handles stainless steel and hardened materials without rapid edge breakdown
• 135-degree split point reduces thrust force and eliminates the need for a center punch on most metals
• Regular spiral flute geometry promotes consistent chip evacuation in through-hole drilling
• Oxide finish provides mild lubricity and corrosion resistance during storage and use
• Straight cylindrical shank fits standard 3-jaw drill chucks without adapters
• Heavy-duty grade rating suitable for production and maintenance drilling cycles

Compatibility

Designed as a jobber-length cobalt drill bit for use in standard drill chucks accepting straight-shank tooling in the 7.00 to 8.00 mm diameter range.

Installation Notes

This bit is installed and removed by a qualified machinist or maintenance technician using a standard keyed or keyless drill chuck. Ensure the drill motor or press is powered down and the chuck is fully secured before beginning any operation. Apply cutting fluid or paste when drilling stainless steel or hardened materials to extend tool life and prevent work hardening at the cut zone. Do not force the bit through the material at excessive feed rates, as cobalt tooling can fracture under lateral loading.