Guhring 9055200079000 Cobalt Stub Drill Bit 0.311 in

Product Description

The GUHRING 9055200079000 is a cobalt stub-length (screw machine length) drill bit designed for high-productivity drilling in metalworking and light industrial applications. Built to DIN 1897 standards, it measures 0.311 inches (7.90 mm) in diameter with an overall length of 79.00 mm and a flute length of 37.00 mm. The four-facet split point at 118 degrees reduces walking and cutting force, while the web-thinned, tapered web construction improves chip evacuation. This bit is used by machinists, tool-and-die technicians, and maintenance professionals who need a rigid, short-body drill for accurate hole entry and high feed rates.

The 9055200079000 is suited for drilling aluminum and similar non-ferrous and light ferrous materials in screw machine, CNC, and manual drill press setups. Its stub-length body minimizes deflection in close-tolerance work where a jobber-length bit would flex or wander. The straight cylindrical shank fits standard drill chucks and collet holders without modification. The 3xD flute-to-diameter ratio supports chip clearance in moderate-depth holes up to 0.99 inches (25.15 mm) maximum drilling depth. Series 5520 identifies this as a standard production-grade offering within the GUHRING stub drill line.

Key Features

• Cobalt tool material for heat and wear resistance in demanding drilling cycles
• Four-facet split point at 118 degrees reduces thrust and self-centers on entry
• Web-thinned tapered web improves chip flow and reduces cutting torque
• Stub-length body (DIN 1897) increases rigidity and reduces deflection versus jobber drills
• Straight cylindrical shank fits standard chucks and collet tool holders
• Right-hand spiral flute with regular helix for consistent chip evacuation

Compatibility

Designed as a DIN 1897 stub-length replacement drill bit suitable for use in CNC machining centers, screw machines, and manual drill presses equipped with standard drill chucks or collet holders accepting a 7.90 mm straight cylindrical shank.

Installation Notes

Installation and use of this drill bit should be performed by qualified machinists or maintenance technicians familiar with rotating cutting tool safety. Ensure the machine spindle is fully stopped and power is locked out before loading or removing the bit from the chuck or collet. Verify chuck or collet bore size matches the 7.90 mm shank diameter before tightening. Do not exceed the recommended maximum drilling depth of 0.99 inches to avoid chip packing or tool breakage.