Guhring 9038990007400 Micro Drill Bit No. 69 Solid Carbide

Product Description

The GUHRING 9038990007400 is a solid carbide micro drill bit designed for precision drilling in tight-tolerance applications. Built to Series 3899 specifications, it carries a No. 69 wire-gauge designation with a decimal diameter of 0.0291 inches and a 140-degree faceted point angle. The TiAlN coating improves heat resistance and extends tool life in abrasive or high-speed cutting environments. With an overall length of 38 mm and a straight-cylindrical shank, this bit seats securely in standard drill chucks and collet holders. Web thinning reduces thrust force at entry and helps maintain hole positional accuracy. Machinists and tool-and-die professionals working with close-tolerance small-diameter holes will find this bit suited to production and precision rework tasks.

This drill bit is intended for use in small-hole drilling operations on primary workpiece materials including cast iron and steel. It is well suited for CNC machining centers, drill presses, and precision hand-held drilling fixtures where a straight-cylindrical shank bit is required. The 5xD flute-by-diameter ratio and spiral flute geometry support chip evacuation in shallow-to-moderate drilling depths up to 6.89 mm. No coolant-through capability is present, so external coolant or cutting fluid should be applied when drilling in production volumes or harder steel grades.

Key Features

• No. 69 wire size, 0.0291 inch decimal diameter with h7 diameter tolerance for close-fit applications
• 140-degree faceted point angle with web thinning to reduce entry thrust and improve positional accuracy
• TiAlN coating for elevated heat resistance and extended tool life in cast iron and steel
• Solid carbide K40 grade construction for rigidity and wear resistance in small-diameter drilling
• Straight-cylindrical shank with 3 mm shank diameter for compatibility with standard collets and chucks
• Spiral flute with regular spiral type promotes chip evacuation throughout the cutting depth

Compatibility

Designed as an OEM-style precision micro drill bit in GUHRING Series 3899, suitable for use in CNC machining centers and precision drilling fixtures that accept a 3 mm straight-cylindrical shank. Rated for primary workpiece materials cast iron and steel per material codes K and P.

Installation Notes

Installation should be performed by a qualified machinist or tooling technician. Ensure the machine spindle is fully stopped and locked out before inserting or removing the bit from the collet or chuck. Confirm shank seating depth and runout with a dial indicator before production drilling to preserve h7 hole tolerance. Because this bit has no coolant-through capability, apply external cutting fluid at the drill point when working in steel or during extended production runs to manage heat buildup.