Osg HP255-3858 Solid Carbide Jobber Drill Bit Letter W

Product Description

The OSG HP255-3858 is a solid carbide jobber-length drill bit sized to Letter W (0.3858 inches / 9.80 mm) and designed for high-performance drilling in ferrous materials. It features a 140-degree point angle with R-thinned web geometry for improved self-centering and reduced thrust on entry. The WD1 coating extends tool life when cutting steel, alloy steel, and cast iron. With an overall length of 103 mm and a 2-flute regular spiral configuration, this bit is built for productive use in CNC machining centers and production drilling applications where consistency and hole quality matter.

This bit is suited for blind hole, cross hole, and through-hole drilling operations in steel and cast iron workpieces. The straight-cylindrical shank (10.00 mm diameter) fits standard drill chucks and collet holders commonly found in vertical machining centers and drill presses. The 5xD flute-to-diameter ratio and tapered web design support chip evacuation in deeper holes. Coolant-through capability makes it compatible with through-spindle coolant setups, helping maintain cutting temperatures and extend service intervals in production environments.

Key Features

• Solid carbide construction for rigidity and wear resistance in ferrous materials
• WD1 coating optimized for cutting steel, alloy steel, and cast iron
• 140-degree point angle with R-thinned web for self-centering and reduced entry thrust
• Coolant-through design compatible with through-spindle coolant systems
• 5xD flute ratio with tapered web supports chip flow in blind and cross-hole applications
• Straight-cylindrical shank fits standard chucks and collet holders

Compatibility

Designed for use in steel, alloy steel, and cast iron workpieces (material codes P and K). Suitable for CNC machining centers, drill presses, and similar equipment accepting a 10.00 mm straight-cylindrical shank. Intended for blind hole, cross hole, drilling, and self-centering operations within the OSG HP255 series.

Installation Notes

Installation and operation should be performed by qualified machinists familiar with carbide tooling. Secure the shank fully in a clean, properly sized collet or chuck before running the spindle. Carbide is brittle compared to high-speed steel — avoid side loads, interrupted cuts without proper setup, and dropping the bit on hard surfaces. When using through-spindle coolant, verify coolant pressure and flow rate are within the machine's rated range before beginning the cut.