Guhring 9012420079000 Screw Machine Drill Bit 0.311in Carbide

Product Description

The GUHRING 9012420079000 is a screw machine length drill bit designed for high-precision drilling in metalworking and machining applications. Built from submicron solid carbide and coated with TiN (titanium nitride), it delivers extended tool life and reduced friction at the cutting edge. The bit features a 140-degree split point (SU type) with web thinning for fast penetration and reduced thrust. At 0.311 inches (7.90 mm) in diameter with an overall length of approximately 3.11 inches (79.00 mm), it fits standard machine tool chucks and is suited for automated and manual drilling cycles. Machinists, tool-and-die workers, and CNC operators are the primary users.

This drill bit is intended for use in machine shops, production environments, and precision fabrication settings. The screw machine length (stub) design provides rigidity in tight setups where a longer jobber-length bit would flex or chatter. Primary workpiece materials include brass, cast iron, and steel. The 3xD flute-to-diameter ratio and spiral flute geometry promote chip evacuation in these materials. It is suitable for drilling operations on mills, drill presses, lathes, and CNC machining centers. Coolant-through is not supported on this bit, so flood or mist coolant at the exterior is the appropriate cooling method.

Key Features

• Submicron solid carbide construction for rigidity and wear resistance in ferrous and non-ferrous metals
• TiN coating reduces friction and extends cutting edge life
• 140-degree SU split point with web thinning minimizes entry thrust and self-centers on the workpiece
• Straight-cylindrical shank fits standard drill chucks and collets without special toolholding
• Parallel web configuration and regular spiral flute promote consistent chip flow
• Conforms to DIN 6539 specification for dimensional consistency

Compatibility

Designed as an OEM-style screw machine length drill bit for use in standard drill chucks and collets accepting a 0.311-inch straight-cylindrical shank. Primary workpiece materials rated by the manufacturer are brass, cast iron, and steel.

Installation Notes

Installation is performed by machinists or CNC operators following standard toolchange procedures. Ensure the machine spindle is fully stopped and locked out before inserting or removing the bit from the chuck or collet. Verify chuck or collet runout is within acceptable tolerance before drilling, as solid carbide bits are more sensitive to runout than high-speed steel. Coolant-through is not available on this bit; apply flood or mist coolant externally to manage heat at the cutting zone.