Hertel 71206155 Jobber Drill Bit Letter X 0.397 Hss

Product Description

The HERTEL 71206155 is a jobber-length twist drill bit sized to Letter X, equivalent to 0.3970 inches decimal diameter. Built from high speed steel with an oxide coating, this bit is designed for general-purpose drilling in metal, wood, and plastics. It features a 118-degree standard point angle, a two-flute regular spiral configuration, and a web-thinned tapered web that reduces thrust and improves chip clearance at the tip. The straight-cylindrical shank seats directly into standard three-jaw drill chucks without an adapter. At 5.125 inches overall length with a 3.75-inch flute length, it covers typical jobber-length drilling applications across a wide range of materials.

This bit suits metal fabrication shops, maintenance trades, HVAC installers, plumbers, and electricians performing field drilling tasks. Its 0.3970-inch diameter falls within the 0.3500 to 0.4000 inch size range commonly needed for bolt clearance holes, conduit knockouts, and fitting preparation. The right-hand cut and standard point geometry make it compatible with most corded and cordless drill drivers and drill presses found in trade and light industrial environments.

Key Features

• Letter X size at 0.3970 inches decimal diameter for precise hole sizing
• 118-degree standard point angle for general-purpose drilling across multiple materials
• High speed steel construction with oxide coating for improved surface hardness and heat resistance
• Web-thinned tapered web reduces drilling thrust and aids chip ejection
• Regular two-flute spiral design maintains chip flow and cutting efficiency
• Straight-cylindrical shank fits standard three-jaw chucks without adapters

Compatibility

Designed as a general-purpose jobber-length drill bit compatible with standard three-jaw drill chucks and drill press spindles accepting straight-cylindrical shanks up to 0.3970 inches in diameter.

Installation Notes

Install and removal should be performed with the drill unpowered and the chuck key fully removed before operation. Secure the shank fully in the chuck jaws and confirm concentricity before drilling. Use appropriate cutting fluid when drilling ferrous metals to extend bit life and manage heat buildup. Follow applicable workplace safety standards and wear eye protection during all drilling operations.