Cleveland C15128 Cobalt Screw Machine Drill Bit 38

Product Description

The CLEVELAND C15128 is a screw machine length (stub length) cobalt drill bit designed for high-production drilling in tough materials. Rated to ASME B94.11M, this wire-gauge size 38 bit measures 0.1015 inches in diameter with an overall length of 1-13/16 inches. The 135-degree split point self-centers on contact, reducing the need for a center punch and minimizing walking on flat or curved workpieces. A parabolic flute geometry evacuates chips efficiently, and the web-thinned, parallel-web construction reduces cutting resistance. This bit is suited for machinists, maintenance technicians, and tool-and-die professionals who drill in alloy steel and aluminum on a regular basis.

The C15128 is built for screw machine operations, CNC drilling cycles, and hand-drilling applications where a short, rigid drill is required to control deflection. The abbreviated length relative to jobber bits makes it the preferred choice for close-tolerance work in metal fabrication shops and production environments. Primary workpiece materials listed for this bit are alloy steel and aluminum. The right-hand cutting direction and straight-cylindrical shank with a 0.1015-inch shank diameter are compatible with standard drill chucks and collet systems used in these environments.

Key Features

• Wire size 38 (0.1015 inch diameter) with a diameter tolerance of +0.0000 to -0.0005 inches for consistent sizing
• 135-degree split point for self-centering and reduced thrust force
• Parabolic flute geometry with web thinning for fast chip evacuation and lower cutting resistance
• M42 cobalt high-speed steel construction handles heat buildup in hard and gummy metals
• Screw machine (stub) length of 1-13/16 inches OAL provides added rigidity to minimize deflection
• Conforms to ASME B94.11M and ANSI specification standards

Compatibility

Designed as an OEM-style replacement or direct-use drill bit for standard drill chucks and collet holders accepting a 0.1015-inch straight-cylindrical shank. Suitable for use with alloy steel and aluminum workpieces per Series 2175A application parameters.

Installation Notes

This bit is installed by a machinist or drilling technician into a compatible drill chuck or collet rated for the shank diameter. Ensure the machine spindle is fully stopped and locked out before inserting or removing the bit. Secure the shank to the full depth recommended by the chuck manufacturer to prevent pullout under load. Do not exceed the recommended feed and speed ranges for the workpiece material to avoid premature edge failure in cobalt tooling.