Sandvik Coromant 7781458 Screw Machine Drill Bit 7.14mm

Product Description

The SANDVIK COROMANT 7781458 is a solid carbide screw machine length drill bit engineered for high-performance drilling in metal cutting and machining applications. Built on the CoroDrill 860 platform, it features a 7.14 mm cutting diameter and a dual-layer TiAlSiN and TiSiN coating that resists heat and extends tool life in demanding materials. The 140-degree split point geometry reduces thrust force and improves centering without a pilot hole. With an overall length of 79 mm and a straight-cylindrical shank, this bit is suited for use in CNC machining centers, drill presses, and screw machine setups. Machinists and toolroom professionals are the primary end users.

This drill bit is designed for screw machine length applications requiring precision hole quality and controlled chip evacuation. The 3xD flute-to-diameter ratio and spiral flute geometry support efficient chip removal at moderate to high feed rates. Coolant-through capability makes it well matched to deep-hole applications where heat buildup and chip packing are concerns. Typical use cases include production drilling in steel, stainless steel, cast iron, and similar ferrous materials on manual or CNC equipment. The 8.00 mm straight-cylindrical shank fits standard collet chucks and drill chucks in that bore range.

Key Features

• Solid carbide construction for rigidity and extended tool life versus high-speed steel alternatives
• Dual TiAlSiN and TiSiN coating for high heat resistance and reduced friction at the cutting edge
• 140-degree drill point angle improves self-centering and reduces entry burr
• Coolant-through design channels coolant directly to the cutting zone for deep-hole applications
• Spiral flute geometry promotes consistent chip evacuation at production feed rates
• CoroDrill 860 series grade X1BM — matched to a broad range of ferrous workpiece materials

Compatibility

Designed as an OEM-specified replacement or direct addition within the SANDVIK COROMANT CoroDrill 860 series. Fits toolholders and collet systems accepting an 8.00 mm straight-cylindrical shank. Applicable drill bit size range is 6.50 mm to 8.00 mm per series specification.

Installation Notes

Installation and tool changes should be performed by a qualified machinist with the machine powered down and all energy sources locked out per applicable OSHA lockout/tagout procedures. Secure the shank fully within the collet or chuck to the recommended grip depth before torquing the retention hardware. Verify coolant-through passages are clear and coolant pressure is set according to the machine tool manufacturer guidelines before running the spindle. Inspect the cutting edge for chipping or wear before each use — solid carbide is brittle and should not be forced into interrupted cuts without confirming suitability.