Guhring 9055230070300 Cobalt Jobber Drill Bit Letter J

Product Description

The GUHRING 9055230070300 is a cobalt jobber-length drill bit sized to Letter J (0.2770 inches decimal equivalent) designed for general-purpose drilling in a wide range of metallic and non-metallic workpiece materials. Built to DIN 338 standards and manufactured from M35 cobalt high-speed steel, this bit delivers improved heat and wear resistance compared to standard HSS tooling. The 118-degree four-facet split point geometry promotes accurate self-centering and reduces thrust load at entry, while the web-thinned, tapered web design supports chip evacuation during moderate-depth drilling. The bright uncoated finish is appropriate for applications where coating adhesion or material compatibility is a concern.

This jobber drill is suited for use in production and maintenance environments where Letter J sizing is required for tapping prep, clearance holes, or precision fit work. The 5xD flute-to-diameter ratio and right-hand spiral fluting support chip flow in aluminum, low-carbon steels, cast iron, and non-ferrous alloys as indicated by workpiece material codes K, M, N, and P. The straight-cylindrical shank allows direct mounting in standard drill chucks, collet holders, or keyless chucks without adapter tooling.

Key Features

• M35 cobalt HSS construction for extended tool life in abrasive and work-hardening materials
• 118-degree four-facet split point for self-centering entry and reduced thrust force
• Web-thinned tapered web improves chip clearance and reduces walking on entry
• Right-hand spiral fluting with regular helix for consistent chip evacuation
• Bright uncoated finish — no coating interaction with reactive workpiece materials
• Built to DIN 338 specification with straight-cylindrical shank for universal chuck compatibility

Compatibility

Designed as an OEM-style jobber drill replacement compatible with standard drill chucks and collet holders accepting a straight-cylindrical shank. Suitable for workpiece materials classified under material codes K, M, N, and P including aluminum, cast iron, and non-ferrous alloys per the supplier attribute data.

Installation Notes

Installation is performed by machinists, tool-and-die technicians, and maintenance trades using a standard drill press, CNC machining center, or hand drill with an appropriate chuck. Secure the straight-cylindrical shank firmly in the chuck before use and verify runout if dimensional tolerance is critical. Observe proper cutting speeds and feeds for cobalt HSS tooling relative to the workpiece material — excessive speed without adequate feed increases heat buildup and shortens tool life. This bit does not support coolant-through delivery; apply cutting fluid externally when drilling steels or hard alloys.