Guhring 9055200098000 Cobalt Stub Drill Bit 0.3858 in

Product Description

The GUHRING 9055200098000 is a cobalt screw machine length (stub) drill bit designed for demanding metal cutting applications. Built to DIN 1897 specifications, this two-flute bit measures 0.3858 inches in diameter with a 118-degree four-facet split point and web-thinned, tapered web geometry. The straight-cylindrical shank seats cleanly in standard chucks. At an overall length of 3.508 inches (89.00 mm) and a flute length of 1.693 inches (43.00 mm), the stub profile delivers greater rigidity than jobber-length bits, reducing deflection in short-hole drilling operations. Licensed machinists, maintenance mechanics, and tool-room technicians install this bit where hole location accuracy and tool life matter.

Series 5520 is sized at a letter W designation (0.3858 inches decimal equivalent) and is suited for drilling aluminum and similar non-ferrous and ferrous workpiece materials where a rigid, short-flute drill reduces chatter and improves hole quality. The 3xD flute-to-diameter ratio keeps the cutting zone stable on CNC machining centers, knee mills, drill presses, and handheld power tools. No coolant-through capability is present, so external flood, mist, or cutting fluid application is the standard approach when drilling with this bit.

Key Features

• Cobalt tool material for elevated heat resistance and extended tool life versus standard high-speed steel
• Four-facet split point with web thinning reduces thrust force and improves self-centering at entry
• Stub (screw machine) length provides added rigidity and reduced deflection compared to jobber-length bits
• 118-degree drill point angle suitable for aluminum and a broad range of workpiece materials
• Straight-cylindrical shank compatible with standard drill chucks and collet holders
• DIN 1897 specification with diameter tolerance of +0.000 to -0.022 mm for consistent fit

Compatibility

Designed as an OEM-specification replacement or new-stock drill bit for applications requiring a DIN 1897 stub-length cobalt drill in the 0.3500 to 0.4000 inch diameter range, Series 5520.

Installation Notes

Installation is performed by qualified machinists or maintenance personnel using a properly sized drill chuck or collet rated for the 9.80 mm (0.386 inch) shank diameter. Ensure the machine spindle is fully stopped and locked out before changing tooling. Secure the shank to the full recommended grip depth to prevent pullout under load. Apply appropriate cutting fluid externally, as this bit does not have coolant-through capability.