Hertel 42093 Cobalt Jobber Drill Bit 8.5 Mm 135 Degree

Product Description

The HERTEL 42093 is a cobalt jobber length drill bit sized at 8.5 mm (0.3346 inches) with a 135-degree split point. Built from M35 cobalt steel and finished with an oxide and gold coating, it is designed for drilling tough materials including stainless steel, high-alloy steels, and hardened metals. The two-flute spiral design with a regular helix promotes efficient chip evacuation. Overall length is 117 mm (4.61 inches), with a flute length of 75 mm (2.95 inches). The straight cylindrical shank seats in standard drill chucks. Machinists, maintenance mechanics, and metalworking trades use this bit for general-purpose and demanding production drilling applications.

This drill bit fits into production machining, toolroom work, and field maintenance scenarios where standard high-speed steel tooling lacks the heat and wear resistance needed. The 8.5 mm diameter places it in the 8.00 to 9.00 mm size range, making it a common selection for metric tap clearance holes, reamed bore preparation, and close-tolerance through-holes in ferrous and non-ferrous workpieces. It is sold individually and is compatible with any drill press, CNC machining center, or hand drill with a chuck capacity that accepts the straight cylindrical shank.

Key Features

• M35 cobalt steel construction for improved heat resistance and tool life in hard and abrasive materials
• Oxide and gold coating reduces friction and provides visual wear indication
• 135-degree split point reduces thrust and improves self-centering on hard surfaces
• Two-flute regular spiral promotes positive chip clearance during through-hole drilling
• Straight cylindrical shank fits standard drill chucks without adapters
• No coolant-through requirement simplifies setup in general shop and field environments

Compatibility

Designed as a standard jobber length drill bit for use in any drill press, machining center, or hand drill with a chuck capacity accommodating an 8.5 mm straight cylindrical shank.

Installation Notes

Installation and use should be performed by qualified machinists or mechanics familiar with rotating cutting tools. Secure the workpiece fully before drilling to prevent movement. Use appropriate cutting fluid for ferrous materials to extend tool life, even though the bit does not require coolant-through delivery. Inspect the cutting edges before each use and replace the bit if chipping or excessive wear is observed.