M.a. Ford. 20639060 Screw Machine Drill Bit 25/64 Carbide

Product Description

The M.A. FORD. 20639060 is a solid carbide screw machine length drill bit designed for high-precision, short-reach drilling in demanding industrial and machining applications. Measuring 25/64 inch (0.3906 inches) in diameter with an overall length of 2-3/4 inches, this bit delivers tight diameter tolerances of +0.0000 to -0.0005 inches. The 118-degree faceted drill point and web-thinned, parallel-web construction reduce entry force and improve centering accuracy. With a spiral flute configuration and right-hand cut, it is suited for use in CNC machining centers, drill presses, and manual machine tools. Machinists and tooling professionals are the primary installers and users.

The 20639060 is engineered for short-hole drilling operations where rigidity and concentricity are critical. Its primary workpiece materials include cast iron, non-ferrous metals, stainless steel, and steel, making it a versatile choice across general machining, maintenance shops, and production environments. The Series 206 designation places it within M.A. FORD.'s standard screw machine length carbide drill family. The flute-to-diameter ratio of 3xD and a flute length of 1-1/4 inches are well suited to shallow-to-medium depth holes where chip clearance and tool stiffness must both be maintained.

Key Features

• Solid carbide construction for superior hardness and wear resistance in ferrous and non-ferrous materials
• 118-degree faceted drill point with web thinning for reduced thrust and improved self-centering
• Bright/uncoated finish suitable for use with cutting fluids or dry machining as application requires
• Right-hand spiral flute design promotes efficient chip evacuation during drilling
• Tight diameter tolerance (+0.0000 to -0.0005 inches) for precision-fit hole applications
• Short screw machine length body (2-3/4 inches overall) provides maximum rigidity at the spindle

Compatibility

Designed as an OEM-style replacement and standard tooling selection for screw machine length carbide drill bit applications in the 0.3500 to 0.4000 inch diameter range, compatible with standard straight-shank tool holders and drill chucks accepting a 0.3906-inch shank.

Installation Notes

Installation and use should be performed by qualified machinists or tooling technicians familiar with proper chuck or collet retention for straight-shank carbide tooling. Always ensure the machine spindle is fully stopped and locked out before securing or removing the bit. Carbide tooling is brittle and should not be subjected to side loads, interrupted cuts beyond design parameters, or re-sharpening without proper carbide grinding equipment. Verify tool runout at the shank before production use to protect both the tool and the workpiece.