Accupro A-6120021R Micro Drill Bit No. 91 Solid Carbide

Product Description

The ACCUPRO A-6120021R is a miniature series solid carbide micro drill bit designed for precision drilling in tight-tolerance applications. Ground to a 120-degree point angle with a right-hand spiral flute, this bit cuts cleanly in small-diameter work where rigidity and accuracy are critical. The wire gauge size is No. 91, corresponding to 0.0083 inches in decimal. At 25 mm overall length with a 1.00 mm straight-cylindrical shank, it fits standard micro drill chucks and precision collet holders used by machinists, toolmakers, and electronics assembly technicians. The bright, uncoated carbide finish suits a wide range of base materials.

This drill bit is suited for small-hole drilling in printed circuit boards, instrument components, watch parts, medical device subassemblies, and other applications where hole diameter precision at sub-0.010-inch scales is required. The miniature series designation indicates it is built for use in benchtop drill presses, CNC micro-machining centers, and precision hand pieces where runout and concentricity are tightly controlled. The short 1.10 mm flute length limits deflection and breakage during shallow-penetration passes in hard or brittle substrates.

Key Features

• No. 91 wire size, 0.0083 inches decimal diameter for sub-0.010-inch hole applications
• 120-degree standard point angle for clean entry and reduced walking on hard materials
• Solid carbide construction provides rigidity and wear resistance at micro-scale diameters
• Right-hand cut with regular spiral flute for efficient chip evacuation in shallow holes
• 1.00 mm straight-cylindrical shank fits standard micro collets and precision chucks
• Bright, uncoated finish compatible with a broad range of workpiece materials

Compatibility

Designed for use in precision micro-machining setups, CNC drilling centers, and benchtop drill presses equipped with collet systems or chucks accepting a 1.00 mm straight-cylindrical shank. Intended for single-piece use per package as supplied.

Installation Notes

Installation and use should be performed by qualified machinists or tooling technicians familiar with micro-diameter tooling. Secure the shank fully in a collet or chuck rated for 1.00 mm shanks and verify runout before drilling. At this diameter, excessive feed rate or lateral force will cause immediate breakage. Do not use in handheld rotary tools without a stable drill guide or press fixture.