Precision Twist Drill 5996451 Extra Length Drill Bit

Product Description

The PRECISION TWIST DRILL 5996451 is a high-performance extra length drill bit designed for deep-hole drilling in a wide range of materials. Built from uncoated bright-finish high-speed steel, this bit features a 5/16 inch diameter, a 135-degree split-point tip for self-centering starts without a center punch, and a parabolic flute geometry that promotes aggressive chip evacuation. The 12-inch overall length with a 9-inch flute length makes it well suited for reaching into deep cavities, extended fixtures, or cross-member drilling where standard-length bits fall short. Licensed tradespeople and precision machinists both rely on bits in this class for consistent performance across tough substrates.

This extra length bit is used in metalworking, fabrication, and maintenance operations where standard drill bit reach is insufficient. The parabolic flute and web-thinned, tapered web construction reduce thrust and heat buildup when drilling carbon steel, stainless steel, cast iron, structural steel, hardened steel, and tempered steel. It also performs well in aluminum, aluminum alloy, brass, bronze, magnesium, magnesium alloy, malleable iron, nickel, thermoplastics, thermosetting plastics, and graphite. The right-hand cutting direction suits conventional drill press and handheld drill operation. The Series QC1290P designation identifies this as a 10xD flute-to-diameter ratio design built to ANSI standards.

Key Features

• 135-degree split-point tip for self-centering entry without a pilot hole or center punch
• Parabolic flute geometry for fast, efficient chip removal in deep-hole applications
• Web-thinned tapered web reduces cutting resistance and lowers required thrust force
• 12-inch overall length with 9-inch flute length for extended reach applications
• Bright uncoated high-speed steel construction compatible with a broad range of workpiece materials
• Right-hand cut, straight-cylindrical shank for standard drill chuck compatibility

Compatibility

Designed for use in standard 3-jaw drill chucks accepting a 5/16 inch straight-cylindrical shank. Compatible workpiece materials include aluminum, aluminum alloy, brass, bronze, carbon steel, cast iron, graphite, hardened steel, magnesium, magnesium alloy, malleable iron, nickel, stainless steel, steel, structural steel, tempered steel, thermoplastics, and thermosetting plastics.

Installation Notes

Install in a drill press, milling machine, or handheld drill with a chuck rated for a 5/16 inch straight shank. Secure the workpiece firmly before drilling and confirm the chuck is fully tightened. Apply appropriate cutting fluid when drilling ferrous metals to manage heat and extend tool life. For deep-hole passes, retract the bit periodically to clear chips and prevent flute packing.