Kennametal 6781151 Screw Machine Drill Bit 4.85mm Carbide

Product Description

The KENNAMETAL 6781151 is a screw machine length drill bit engineered for high-performance drilling in steel and other ferrous workpiece materials. Built from solid carbide grade KCP15B, it carries a multi-layer AlTiN and TiN coating that extends tool life and improves heat resistance under demanding cycle times. The 140-degree point angle promotes self-centering and reduces thrust force on entry. At 4.85 mm in diameter with a 66.00 mm overall length (approximately 2.60 inches), this bit fits short-reach applications where rigidity and hole accuracy are critical. It is well suited for CNC machining centers, drill presses, and automated production equipment operated by machinists and tool-and-die professionals.

The 6781151 is designed for stub-length drilling operations in steel primary workpiece applications, including production machining of components, fixtures, and structural steel parts. The screw machine length profile keeps overhang minimal, reducing deflection and improving straightness in through-hole and blind-hole work. The straight cylindrical shank with a 6.00 mm shank diameter seats securely in standard drill chucks and collet holders. A maximum drilling depth of 20.00 mm and a 3xD flute-to-diameter ratio support efficient chip evacuation without packing in short-depth bores.

Key Features

• Solid carbide KCP15B grade for high hardness and wear resistance in steel cutting
• Multi-layer AlTiN and TiN coating reduces heat buildup and extends tool life
• 140-degree standard point angle for accurate self-centering entry
• Screw machine (stub) length body minimizes deflection and improves hole straightness
• Right-hand cut with regular spiral flute geometry for consistent chip evacuation
• Straight cylindrical shank compatible with standard chucks and collet holders

Compatibility

Designed as an OEM-style replacement or direct application tool for machining operations requiring a 4.85 mm carbide drill bit in the KENNAMETAL HPX series, fitting standard drill chucks and collet holders that accept a 6.00 mm straight shank.

Installation Notes

Installation and operation should be performed by qualified machinists familiar with CNC or manual drilling equipment. Ensure the machine spindle is fully stopped and powered down before inserting or removing the bit from the chuck or collet. Verify chuck or collet bore matches the 6.00 mm shank diameter to prevent runout and premature tool wear. Coolant-through is not supported on this bit, so adequate external coolant or air blast should be applied when drilling at production feed and speed rates.