Accupro 4500378 Screw Machine Drill Bit 17/64 in Carbide

Product Description

The ACCUPRO 4500378 is a screw machine length drill bit designed for high-performance drilling in demanding trade and industrial applications. Built from solid carbide with a TiAlN coating, this bit measures 17/64 inches (0.2656 inches) in diameter with a 3.465-inch overall length and a 140-degree split point angle. The shorter-than-jobber-length body gives added rigidity in confined setups such as CNC machining centers, turret lathes, and screw machine operations. Two spiral flutes and R-thinned web geometry promote efficient chip evacuation and reduced thrust. Coolant-through capability supports continuous high-speed operation.

This drill bit is rated for primary use in stainless steels, making it well suited for fabrication shops, maintenance machinists, and production environments where work-hardening materials demand sharper point geometry and superior tool life. The straight-cylindrical shank fits standard drill chucks and collet holders without modification. The 3xD flute-to-diameter ratio and regular spiral type are optimized for short-hole drilling at elevated feed rates where rigidity and runout control matter most.

Key Features

• Solid carbide construction for superior hardness and heat resistance in stainless steel applications
• TiAlN coating extends tool life by reducing friction and thermal buildup at the cutting edge
• 140-degree split point angle reduces walking and lowers required thrust on entry
• R-thinned web geometry improves chip flow and reduces axial cutting force
• Coolant-through design supports high-speed operation and extends tool life in production drilling
• Screw machine length body provides added rigidity over jobber-length bits in tight or fixtured setups

Compatibility

Designed for use in CNC machining centers, turret lathes, and screw machines equipped with standard straight-cylindrical shank toolholders or collet chucks accepting a 0.2656-inch shank diameter. Primary workpiece material is stainless steels per ISO specification designation.

Installation Notes

Installation and use should be performed by qualified machinists or tooling technicians familiar with cutting tool safety practices. Ensure the machine spindle is fully stopped and locked out before inserting or removing the bit from the chuck or collet holder. Verify chuck runout is within acceptable limits before operation, as excess runout accelerates carbide wear and risks tool breakage. Always engage coolant flow before contact with the workpiece when using the coolant-through feature.