Osg HP253-3858 Carbide Screw Machine Drill Bit 0.3858 in

Product Description

The OSG HP253-3858 is a solid carbide screw machine length drill bit designed for high-performance drilling in demanding metalworking applications. It features a 0.3858 inch (Letter W / 9.80 mm) diameter, a 140-degree split point, and a right-hand spiral flute geometry with R-thinned web for reduced thrust and improved chip evacuation. Coolant-through capability supports extended tool life in production environments. With an overall length of 89.00 mm and a straight-cylindrical shank diameter of 10.00 mm, this bit is built for precision, high-cycle drilling where rigidity and dimensional accuracy are critical.

This drill bit is suited for machining steel, alloy steel, and cast iron in production shop, job shop, and CNC machining center environments. The screw machine length (stub) configuration provides maximum rigidity for tight-tolerance holes. The 3xD flute-to-diameter ratio and tapered web construction make it well suited for short-hole drilling operations where runout and deflection must be minimized. It is typically installed and operated by machinists and toolroom professionals working with ferrous workpiece materials.

Key Features

• Solid carbide construction for rigidity and wear resistance in ferrous materials
• 140-degree point angle with R-thinned web reduces entry thrust and improves centering
• Coolant-through design supports high-speed production drilling and extended tool life
• Screw machine (stub) length provides maximum rigidity and minimal deflection
• Right-hand cut with regular spiral flute for consistent chip flow
• Diameter tolerance of +0.006 to +0.021 mm for close-tolerance hole requirements

Compatibility

Designed for drilling steel, alloy steel, and cast iron workpieces. Fits standard straight-cylindrical shank tool holders with a 10.00 mm bore. Suitable for CNC machining centers and manual drill press setups configured for carbide tooling and through-spindle or external coolant delivery.

Installation Notes

Installation and operation should be performed by qualified machinists familiar with carbide tooling requirements. Ensure the tool holder bore and shank are clean and free of debris before securing the bit. Carbide tooling is brittle and should never be used in machines with excessive runout or vibration. Always verify coolant flow is active before engaging the cut when using the through-coolant feature.