M.a. Ford 20643750 Screw Machine Drill Bit 7/16 Carbide

Product Description

The M.A. FORD 20643750 is a screw machine length drill bit designed for high-precision drilling in demanding shop and field applications. Built from solid carbide with a bright/uncoated finish, it delivers rigidity and edge retention that high-speed steel cannot match on hard or abrasive materials. The bit measures 0.4375 inches (7/16 inch) in diameter with an overall length of 2.75 inches and a flute length of 1.25 inches. A 118-degree faceted point angle provides reliable centering without a pilot, and the web-thinned parallel web reduces thrust force at entry. Right-hand spiral flutes evacuate chips cleanly throughout the cut. This is a production-grade tool used by machinists, tool-and-die workers, and maintenance mechanics.

The 20643750 is suited for drilling cast iron, non-ferrous metals such as aluminum, brass, and copper, and a range of plastics. The screw machine length profile — shorter than a jobber-length bit — increases rigidity and reduces deflection in close-tolerance work, making it a practical choice for CNC machining centers, drill presses, and manual turret lathes where stub-length tooling is preferred. The straight cylindrical shank seats directly in standard drill chucks and collet holders without adaptation. Diameter tolerance is held to +0.0000 to -0.0005 inches for controlled hole sizing.

Key Features

• Solid carbide construction for superior hardness and wear resistance over HSS on abrasive workpiece materials
• 118-degree faceted drill point with web thinning to reduce entry thrust and improve centering
• Screw machine (stub) length at 2.75 inches overall minimizes deflection in tight setups
• Right-hand spiral flutes with regular helix for consistent chip evacuation
• Diameter tolerance of +0.0000 to -0.0005 inches supports close-tolerance hole requirements
• Bright/uncoated finish compatible with a wide range of cutting fluids and dry-cut applications

Compatibility

Designed for use on cast iron, non-ferrous metals, and plastics. Fits standard drill chucks and collet holders accepting a straight cylindrical shank at 0.4375 inches diameter. Part of M.A. FORD Series 206 screw machine length carbide drill bits covering the 0.4000 to 0.4500 inch diameter range.

Installation Notes

Secure the shank fully in the chuck or collet before operation and verify runout before cutting. Solid carbide tooling is brittle — avoid side loading, interrupted cuts beyond the tool rating, or using the bit as a pry. Use appropriate speeds and feeds for the workpiece material; carbide generally runs at higher surface footage than HSS but requires a rigid, vibration-free setup. Eye protection and chip guards are required whenever the tool is in operation.