Hertel 84578525 Jobber Drill Bit Letter B Hss Tin 4in

Product Description

The HERTEL 84578525 is a jobber-length twist drill bit sized to Letter B (0.2380 inches decimal equivalent), designed for general-purpose hole-making in metal, wood, and composite materials. The bit is manufactured from high speed steel (HSS) with a titanium nitride (TiN) coating that increases surface hardness and extends tool life in repetitive drilling applications. It features a standard 118-degree point angle, a web-thinned and tapered web configuration for easier penetration and reduced thrust, and a right-hand spiral flute geometry for efficient chip evacuation. The 4-inch overall length and straight-cylindrical shank make it compatible with standard three-jaw drill chucks. Machinists, maintenance technicians, and general tradespeople are the primary users.

This drill bit is suited for light-to-medium duty drilling in ferrous and non-ferrous metals, plastics, and similar materials on the shop floor or job site. The Letter B sizing places it in the 0.2000 to 0.2500 inch range, making it a common selection for clearance holes, pilot holes, and tapping operations requiring precise decimal sizing. The 4-inch jobber length provides a practical balance between rigidity and reach for bench drilling, hand-held drill use, and drill press operations.

Key Features

• Letter B size — 0.2380 inches decimal equivalent for precise fit requirements
• TiN coating reduces friction and increases wear resistance compared to uncoated HSS
• 118-degree standard point angle suited for general-purpose drilling across multiple materials
• Web-thinned, tapered web lowers entry force and reduces walking on flat surfaces
• Right-hand cut with regular spiral flutes for reliable chip clearance
• Straight-cylindrical shank fits standard drill chucks without adapters

Compatibility

Designed as a general-purpose jobber-length drill bit compatible with any standard three-jaw drill chuck or collet system accepting a 0.2380-inch straight shank, including bench drill presses, hand drills, and CNC drill stations within the appropriate size range.

Installation Notes

A licensed machinist or qualified tradesperson should secure the shank fully in the chuck and verify concentricity before operation. Always wear appropriate eye protection and ensure the workpiece is clamped before drilling. Use cutting fluid when drilling hard metals to preserve the TiN coating and extend bit life. Inspect the cutting edges for wear or chipping before each use and replace the bit if the point is damaged.