Guhring 9055200070000 Cobalt Stub Drill Bit 0.2756 in

Product Description

The GUHRING 9055200070000 is a cobalt stub-length drill bit built for demanding metal-cutting applications where rigidity and heat resistance matter. Ground to a 118-degree four-facet split point with web thinning, this bit starts on center without a pilot and reduces thrust force through the cut. At 7.00 mm (0.2756 inches) in diameter with a straight-cylindrical shank of the same diameter, it seats cleanly in standard drill chucks and collets. The two-spiral flutes run a 3xD ratio, supporting a maximum drilling depth of 0.925 inches (23.50 mm). Manufactured to DIN 1897 specification, the bit carries a cobalt tool material construction that maintains hardness at elevated cutting temperatures. HVAC, plumbing, and general metalworking mechanics reach for this geometry when short, stiff reach is more important than depth.

This bit is suited for drilling aluminum as its primary workpiece material, though the cobalt construction and four-facet split-point geometry also perform in a range of non-ferrous and ferrous metals encountered in trade fabrication and field work. The stub (screw-machine) length body reduces deflection in tight clearance situations, making it a practical choice for panel drilling, fixture work, and structural steel applications where a jobber-length bit would flex or chatter. Right-hand cut, regular spiral flute configuration handles chip evacuation efficiently at standard feed and speed rates.

Key Features

• Cobalt tool material retains hardness under high-heat cutting conditions
• 118-degree four-facet split point with web thinning for self-centering entry and reduced thrust
• Stub length body minimizes deflection and improves rigidity in tight spaces
• Straight-cylindrical shank at 7.00 mm fits standard chucks and collets without adapters
• DIN 1897 specification ensures consistent dimensional tolerances across the series
• Tapered web configuration with web thinning supports clean chip formation and flute evacuation

Compatibility

Designed as a DIN 1897 stub-length drill bit in Series 5520, sized for use in any standard drill chuck or collet accepting a 7.00 mm straight-cylindrical shank. Fits the 0.2500 to 0.3000 inch (6.50 to 8.00 mm) drill diameter range.

Installation Notes

Secure the shank fully in a chuck or collet before operation and verify concentricity to avoid premature edge wear. Power down and de-energize any machine spindle before bit changes. Follow applicable shop safety standards and machine manufacturer guidelines for feed rate and RPM when drilling cobalt bits into ferrous materials. Coolant-through is not supported on this bit; use external coolant or cutting fluid as appropriate for the workpiece material.