Guhring 9055230030500 Cobalt Jobber Drill Bit No. 31

Product Description

The GUHRING 9055230030500 is a cobalt jobber length drill bit sized at No. 31 (0.1200 inches decimal) with a 118-degree four facet split point. Built to DIN 338 specification and manufactured in M35 cobalt material grade, this bit delivers reliable performance in demanding drilling applications. The right-hand spiral flute design handles chip evacuation efficiently, and web thinning reduces thrust on entry. The straight-cylindrical shank measures 3.05 mm in diameter and seats securely in standard drill chucks. At 65 mm overall length with a 36 mm flute length, it fits standard jobber-length toolholders used by machinists, pipefitters, and maintenance technicians.

This drill bit is rated for use in aluminum, non-ferrous metals, and steel alloys, as reflected in its primary workpiece material codes K, M, N, and P under DIN classification. It is a strong choice for production drilling, maintenance repair, and general fabrication work where consistent hole quality in varied materials is required. The bright uncoated finish keeps the bit well-suited for applications where a coated surface is not needed or preferred. Maximum drilling depth is 31.43 mm (1.237 inches) per pass, appropriate for jobber-length use in a standard drill press, CNC machining center, or handheld drill.

Key Features

• M35 cobalt construction for improved heat and wear resistance versus standard HSS
• 118-degree four facet split point with web thinning for reduced entry thrust and self-centering action
• DIN 338 standard compliance for consistent dimensional accuracy
• Right-hand regular spiral flute with 5xD flute-to-diameter ratio for effective chip clearing
• Bright uncoated finish compatible with a wide range of cutting fluids and workpiece materials
• Diameter tolerance of +0.000 to -0.018 mm for close-tolerance hole work

Compatibility

Designed as a DIN 338 jobber length replacement drill bit compatible with standard straight-shank drill chucks and toolholders accepting a 3.05 mm shank diameter across drill presses, CNC machining centers, and handheld drills.

Installation Notes

Installation and use should be performed by a qualified machinist or tradesperson familiar with cutting tool safety. Always secure the workpiece before drilling and confirm the chuck is tightened to the shank fully before operation. Apply appropriate cutting fluid for the workpiece material to extend tool life. Inspect the cutting edges for wear or chipping before each use and replace the bit if geometry is compromised.