Guhring 9055200039900 Cobalt Stub Drill Bit 0.157 in

Product Description

The GUHRING 9055200039900 is a cobalt screw machine length (stub) drill bit designed for precision drilling in demanding shop and production environments. Built to DIN 1897 standards, this 0.157 inch diameter bit features a 118-degree four facet split point and web-thinned, tapered web construction that reduces thrust force and improves centering accuracy. The straight-cylindrical shank and regular spiral flute geometry support consistent chip evacuation. With a two-flute spiral design and an overall length of approximately 2.165 inches (55.00 mm), it is well suited for high-cycle drilling operations where rigidity and tool life matter. Licensed machinists, tool-and-die technicians, and production line operators are the primary users.

This stub length drill bit is optimized for aluminum and other non-ferrous materials but performs across a broad range of workpiece materials where cobalt tooling is specified. The compact flute length of approximately 0.866 inches (22.00 mm) provides added rigidity compared to jobber-length bits, making it appropriate for CNC machining centers, drill presses, and screw machines operating in tight-clearance fixtures. Maximum drilling depth is 0.631 inches (16.02 mm). Wire gauge sizing as No. 22 places it within the 0.150 to 0.200 inch decimal inch range, a common size band in precision hole applications.

Key Features

• Cobalt tool material provides elevated heat resistance for extended tool life in production drilling
• Four facet split point with web thinning reduces entry thrust and improves hole location accuracy
• DIN 1897 stub length standard delivers greater rigidity than jobber-length alternatives
• Right-hand cut, regular spiral flute supports efficient chip evacuation
• Straight-cylindrical shank compatible with standard drill chucks and collet holders
• Diameter tolerance of +0.000 to -0.018 mm ensures consistent close-tolerance hole sizing

Compatibility

Designed as an OEM-style tooling replacement conforming to DIN 1897 stub length specifications; fits standard drill chucks and collet systems accepting a 3.99 mm (approximately 0.157 inch) straight-cylindrical shank. Primary workpiece material designation is aluminum per manufacturer specification.

Installation Notes

Installation and use should be performed by qualified machinists or tooling technicians familiar with rotary cutting tool safety. Ensure the machine spindle is fully stopped and locked out before changing drill bits. Secure the shank firmly in the chuck or collet to the rated holding depth to prevent runout. Do not exceed the maximum drilling depth of 0.631 inches per pass without retracting to clear chips, particularly in blind-hole applications.