Precision Twist Drill 5997556 Screw Machine Drill Bit

Product Description

The PRECISION TWIST DRILL 5997556 is a screw machine length drill bit designed for high-performance drilling in cast iron and steel. Built from high speed steel with a bright, uncoated finish, it features a parabolic flute geometry that promotes fast chip evacuation and reduced heat buildup during extended cuts. The 135-degree split point provides aggressive self-centering entry without requiring a center punch, and the web-thinned, tapered web design reduces thrust force at the tip. At 3/8 inch diameter and 3.125 inches overall length, this bit fits standard screw machine length applications where a shorter body improves rigidity and precision in tight setups.

This drill bit is suited for production drilling, maintenance, and repair operations in shop and field environments. The screw machine length format makes it a common choice on drill presses, CNC machines, and hand drills where a shorter bit reduces deflection. Primary workpiece materials are cast iron and steel, making it appropriate for HVAC, plumbing, and general metalworking trades that need reliable, repeatable hole quality in ferrous materials.

Key Features

• 3/8 inch (0.3750 inch) diameter, screw machine length for increased rigidity
• 135-degree split point for self-centering entry without center punching
• Parabolic flute with 3xD flute-to-diameter ratio for efficient chip evacuation
• Web-thinned, tapered web reduces cutting thrust and tip wear
• High speed steel construction, bright/uncoated finish, right-hand cut
• Straight-cylindrical shank fits standard drill chucks
• Meets ANSI standards; Series QC41P

Compatibility

Designed for use in cast iron and steel workpieces; fits any drill chuck or collet accepting a straight-cylindrical 3/8 inch shank across standard drill presses, CNC equipment, and portable hand drills.

Installation Notes

A licensed or qualified machinist or tradesperson should select the correct cutting speed and feed rate for the workpiece material before use. Secure the workpiece firmly and ensure the chuck is tightened before drilling. Use appropriate cutting fluid or coolant where required by the application, even though this bit does not have through-coolant capability. Inspect the cutting edges for wear before each use and replace the bit if the point is chipped or the flutes are damaged.