Triumph Twist Drill 060425 Screw Machine Drill Bit 25/64

Product Description

The TRIUMPH TWIST DRILL 060425 is a heavy-duty screw machine length drill bit engineered for demanding metal cutting applications. Built from high speed steel with a coated finish, this bit features a 135-degree split point and a web-thinned, tapered web configuration that reduces thrust and improves chip evacuation at entry. The 25/64-inch (0.3906-inch) diameter and compact screw machine length body make it well suited for high-torque drilling in tight-clearance setups. Right-hand spiral flute geometry promotes smooth cutting and consistent hole quality. Machinists and toolroom technicians reach for the T4HD series when drilling superalloys and other difficult materials that demand a heavier-built bit.

This bit is rated for use in superalloy workpiece materials, where standard general-purpose bits often deflect or wear prematurely. The screw machine length profile keeps the bit rigid and minimizes runout, making it a common choice for CNC machining centers, drill presses, and manual lathes where stub-length rigidity is required. The straight-cylindrical shank fits standard drill chucks without an adapter. It is sold individually and is appropriate for production-floor tooling as well as maintenance and repair operations.

Key Features

• 25/64-inch (0.3906-inch) diameter, sized for hole tolerances in the 0.3500 to 0.4000-inch range
• 135-degree split point reduces walking and lowers required entry thrust
• Web-thinned tapered web improves chip flow and reduces heat buildup at the tip
• High speed steel construction with coated finish for improved wear resistance
• Screw machine (stub) length body increases rigidity and reduces deflection
• Right-hand spiral flute, regular helix, compatible with standard drill chucks
• T4HD heavy-duty series designation indicates reinforced geometry for difficult materials

Compatibility

Designed as a heavy-duty screw machine length replacement or tooling-room bit for applications involving superalloys and similarly tough workpiece materials. Straight-cylindrical shank fits standard 3-jaw drill chucks and collet systems accepting bits up to 0.3906 inches in diameter.

Installation Notes

Installation and use of this drill bit should be performed by qualified machinists or toolroom technicians familiar with cutting tool setup and machine operation. Ensure the drill chuck or collet is clean and fully seated before tightening, and verify that the machine spindle is at a full stop before changing tooling. Cutting fluid or coolant is recommended when drilling superalloys to manage heat and extend tool life, even though this bit does not feature through-coolant capability. Always inspect the cutting edges for wear before each use and replace the bit if chipping or excessive dullness is observed.