Osg HP243-1535 Screw Machine Drill Bit 3.90mm Carbide

Product Description

The OSG HP243-1535 is a screw machine length drill bit designed for high-productivity drilling in steel, alloy steel, and cast iron. Built from solid carbide and coated with OSG's proprietary multi-layer EgiAs coating, this bit delivers extended tool life in demanding production environments. The 140-degree point angle with R-thinned web reduces thrust and improves chip evacuation at entry. At 3.90 mm in diameter with a 66.00 mm overall length, it fits standard straight-shank tool holders and is sized for short, rigid setups typical of screw machine and CNC drilling operations. Licensed machinists and toolroom technicians are the primary users of this bit.

This drill bit is suited for production drilling in ferrous materials including mild steel, alloy steel, and cast iron. The screw machine length format — shorter than jobber-length bits — provides added rigidity and is a common choice for CNC machining centers, turret lathes, screw machines, and drill presses where minimizing deflection is critical. The 2-flute regular spiral geometry handles a wide range of hole depths up to approximately 3 times the diameter per pass without coolant-through capability, making it appropriate for through-hole and shallow blind-hole applications.

Key Features

• Solid carbide construction for rigidity and wear resistance in ferrous materials
• Proprietary multi-layer EgiAs coating extends tool life in steel and alloy steel
• 140-degree point angle with R-thinned web reduces entry thrust and improves centering
• Screw machine length for maximum rigidity in short-reach drilling setups
• Straight shank at 6.00 mm diameter fits standard collet and chuck toolholders
• 2-flute regular spiral geometry supports efficient chip clearance in production drilling

Compatibility

Designed for use in steel, alloy steel, and cast iron workpieces. Fits standard straight-shank tool holders accepting a 6.00 mm shank. Part of the OSG HP243 series covering the 3.50 mm to 5.00 mm diameter range.

Installation Notes

Install in a collet chuck or keyed drill chuck rated for the 6.00 mm straight shank before energizing the spindle. Ensure the tool holder is clean and free of chips before seating the shank to prevent runout. Solid carbide tooling is brittle — avoid side loads and interrupted cuts that exceed the bit's designed feed and speed parameters. Follow your machine tool manufacturer's guidelines and applicable shop safety procedures when setting speeds, feeds, and depth of cut.