Cleveland C71088 Jobber Drill Bit Letter R Hss Oxide

Product Description

The CLEVELAND C71088 is a jobber-length twist drill bit sized to letter R (0.3390 inches decimal), manufactured from high speed steel with an oxide coating for improved wear resistance. It features a 118-degree standard point angle, a web-thinned and tapered web configuration for easier penetration, and a regular spiral with two flutes for efficient chip evacuation. The straight-cylindrical shank seats directly into standard drill chucks. This is a general-purpose bit suited for production and maintenance drilling in metal, wood, and plastics. Machinists, maintenance technicians, and trade professionals install it wherever a repeatable letter-R diameter hole is required.

The C71088 is designed for general-purpose drilling in a wide range of shop and field applications. The 4.75-inch overall length and 3.4375-inch flute length accommodate typical workpiece thicknesses encountered in HVAC fabrication, plumbing rough-in, electrical panel work, and general mechanical assembly. The right-hand cut and regular spiral make it compatible with standard variable-speed drill presses, hand drills, and CNC drilling operations.

Key Features

• Letter R size — 0.3390 inches decimal diameter with a tolerance of -0.0010 to 0.0000 inches
• 118-degree standard point angle with web-thinned, tapered web for reduced entry force
• High speed steel construction with oxide coating for extended service life
• Two-flute regular spiral design promotes consistent chip clearance
• Straight-cylindrical shank for secure seating in standard drill chucks
• Meets ASME B94.11M and DIN 338 standards for jobber-length drill bits

Compatibility

Designed as a general-purpose jobber-length drill bit compatible with any standard drill chuck accepting a 0.3390-inch straight-cylindrical shank, including benchtop drill presses, hand-held power drills, and CNC drilling equipment.

Installation Notes

A licensed machinist or qualified tradesperson should secure the shank fully in the chuck and verify concentricity before drilling. Ensure the workpiece is clamped or fixtured to prevent movement during operation. Apply appropriate cutting fluid when drilling ferrous metals to extend bit life and maintain dimensional accuracy. Do not exceed the recommended feed rate for the material being drilled, and inspect the cutting edges for wear before each use.