Precision Twist Drill 5998741 Drill Bit Letter C Hss

Product Description

The PRECISION TWIST DRILL 5998741 is a jobber-length twist drill bit sized at Letter C (0.2420 inches) designed for general-purpose drilling in metal and hard materials. Built from high speed steel with a steam oxide coating, it runs a 135-degree split-point tip that reduces walking on contact and lowers the thrust needed to start a hole. The right-hand spiral flute geometry evacuates chips efficiently during through-hole and blind-hole drilling. With an overall length of 4 inches and a flute length of 2.75 inches, it fits standard drill chucks and magnetic-base drill setups used daily in fabrication and maintenance work.

This bit is suited for production and job-site drilling in steel, stainless steel, cast iron, non-ferrous metals, superalloys, and titanium. The straight-cylindrical shank at 0.2420 inches diameter seats directly in three-jaw chucks without adapters. Series R10B-R15B-R18B construction meets ANSI and NAS 907 standards, making it appropriate for aerospace, industrial fabrication, pipefitting, and HVAC sheet-metal applications where consistent hole sizing and bit longevity under repeated use are required.

Key Features

• Letter C size — 0.2420 inches decimal equivalent for precise hole sizing
• 135-degree web-thinned split point reduces walking and lowers entry thrust
• High speed steel construction with steam oxide coating for heat and wear resistance
• Right-hand, 2-flute regular spiral design for efficient chip evacuation
• Straight-cylindrical shank fits standard 3-jaw drill chucks without adapters
• Meets ANSI and NAS 907 standards — rated for steel, stainless, cast iron, non-ferrous metals, superalloys, and titanium

Compatibility

Designed as a general-purpose OEM-style jobber drill bit compatible with standard 3-jaw chucks, drill presses, hand drills, and magnetic-base drills that accept straight-cylindrical shanks. Rated for use in steel, stainless steel, cast iron, non-ferrous metal, superalloys, and titanium workpiece materials per NAS 907 and ANSI specifications.

Installation Notes

Machinists, fabricators, pipefitters, and HVAC sheet-metal technicians are the typical users of this bit. Secure the shank fully in the chuck before operation and confirm chuck jaws are tightened evenly. Use appropriate cutting fluid or coolant when drilling stainless steel, superalloys, or titanium to manage heat buildup and extend bit life. Inspect the cutting edges and web area for wear or chipping before each use and replace the bit if the point is damaged.