Accupro A-6120041R Micro Drill Bit No. 78 0.0161 in

Product Description

The ACCUPRO A-6120041R is a solid carbide micro drill bit designed for precision drilling in miniature and tight-tolerance applications. Ground to wire gauge size No. 78 with a decimal diameter of 0.0161 inches, this bit features a 120-degree drill point angle and a spiral flute configuration for consistent chip evacuation. The straight cylindrical shank measures 1.00 mm in diameter, and the overall length is 25.00 mm. Bright and uncoated, it is suited for use in materials where a coated surface would not provide additional benefit. Right-hand cutting direction follows standard CNC and manual drill press conventions. Machinists and tool-and-die professionals are the primary installers.

This micro drill bit is used in precision machining environments where very small hole diameters are required. Typical applications include printed circuit board drilling, instrument manufacturing, watchmaking, medical device fabrication, and fine metalwork. The miniature series designation indicates it is engineered for controlled, low-feed-rate operations on bench-top mills, CNC machining centers, and precision drill presses. It is not intended for heavy-duty production drilling or impact-style driving. Coolant-through capability is not included, so external or flood coolant methods apply where needed.

Key Features

• Solid carbide construction provides rigidity and wear resistance at very small diameters
• Wire gauge size No. 78 at 0.0161 inch decimal diameter for tight-tolerance hole requirements
• 120-degree drill point angle suited for standard through-hole and blind-hole drilling
• Spiral flute type with regular spiral for reliable chip evacuation in miniature bores
• Bright and uncoated finish for direct use without surface interaction concerns
• Straight cylindrical shank at 1.00 mm diameter for secure collet or chuck retention

Compatibility

Designed as a miniature-series replacement or stock drill bit for precision machining setups requiring a No. 78 wire gauge diameter. Fits standard collets and drill chucks rated for a 1.00 mm shank diameter on CNC machining centers, bench mills, and precision drill presses.

Installation Notes

Installation and use should be performed by qualified machinists familiar with micro-diameter tooling. Secure the shank in a collet or precision drill chuck rated for 1.00 mm shank diameter before operation; avoid side-loading the bit, as solid carbide is brittle at this diameter. Spindle runout should be minimized to prevent bit deflection or breakage. Always bring the machine to a full stop before changing or inspecting the tool.