Precision Twist Drill 5996525 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5996525 is a cobalt screw machine length drill bit designed for high-performance drilling in hard and abrasive materials. Built to the M42 cobalt grade specification, it runs a 135-degree split point with web thinning to reduce thrust and improve centering on contact. The straight-cylindrical shank seats in standard drill chucks without slippage. At 2-7/16 inches overall length with a 1-5/16 inch flute length, this stub-length geometry delivers improved rigidity over jobber-length bits, making it well suited for production environments where tool deflection and chatter must be controlled.

This drill bit is intended for use on hard materials including hardened steels, stainless steel, and other tough alloys where standard high-speed steel bits underperform or fail prematurely. The screw machine length format is common in CNC drilling, turret lathes, and drill press applications where shorter overhang is required for accuracy and repeatability. The 2.5xD flute-to-diameter ratio and tapered web configuration support chip evacuation in deep-hole applications within this stub-length class. It is sized at 15/64 inch (0.2340 inch decimal, letter size A) and meets ANSI standards for dimensional consistency.

Key Features

• M42 cobalt steel construction for extended tool life in hard and abrasive materials
• 135-degree split point with web thinning reduces walking and lowers required thrust force
• Screw machine (stub) length improves rigidity and minimizes deflection versus jobber-length bits
• Straight-cylindrical shank fits standard 3-jaw drill chucks and collet holders
• Regular spiral flute with tapered web supports chip evacuation during drilling cycles
• Meets ANSI dimensional standards for drop-in replacement in production tooling setups

Compatibility

Designed as a screw machine length replacement drill bit in PRECISION TWIST DRILL Series M42CO, suitable for use in any drill press, CNC machining center, or turret lathe accepting a straight-cylindrical shank bit in the 15/64 inch (0.2340 inch) size class.

Installation Notes

Installation is performed by machinists or tooling technicians in shop and production environments. Ensure the machine spindle is fully de-energized and locked out before changing tooling. Secure the shank fully into the chuck or collet and verify concentricity before running at speed. Cobalt bits are brittle relative to HSS — avoid side-loading or levering the bit during use, as this can cause tip fracture.