Import BDNA--20916-1 5/16 Inch Mechanics Drill Bit Hss

Product Description

The IMPORT BDNA--20916-1 is a 5/16-inch mechanics-length drill bit built for demanding metalworking applications. It is manufactured from high-speed steel with an oxide finish and features a 135-degree split point that reduces walking and requires no center punch on most materials. The Weldon flat shank with three flats locks securely in chuck holders to prevent slipping under torque. Web thinning improves cutting efficiency and reduces the thrust required to penetrate hard stock. This bit is suited for use by machinists, HVAC technicians, plumbers, and electricians who drill through metal framing, enclosures, or structural components in the field or shop.

This mechanics-length drill bit is designed for general-purpose drilling in carbon steel, cast iron, high alloy steel, high tensile strength alloy, stainless steel, and similar ferrous metals. The shorter mechanics length provides added rigidity compared to jobber-length bits, making it well suited for tight-clearance drilling in equipment rooms, panel boxes, and mechanical chases where a longer bit would flex or deflect. The right-hand spiral flute evacuates chips efficiently during through-hole operations.

Key Features

• 135-degree split point reduces bit walking and eliminates the need for a center punch on most metal surfaces
• High-speed steel construction withstands the heat generated when drilling ferrous metals
• Oxide finish provides mild lubricity and corrosion resistance during storage and use
• Weldon flat shank with three flats prevents rotation in compatible chuck holders
• Web-thinned parallel web reduces drilling thrust and improves chip clearance
• Mechanics length (4 inches overall) provides greater rigidity than jobber-length equivalents

Compatibility

Designed as a general-purpose replacement or supplemental mechanics drill bit compatible with 3-flat Weldon shank chuck holders and suitable for drilling carbon steel, cast iron, high alloy steel, stainless steel, and high tensile strength alloy workpieces.

Installation Notes

Installation is performed by machinists and trade professionals using a drill press, magnetic drill, or handheld drill with a compatible Weldon flat chuck. Secure the three-flat shank fully in the chuck before beginning to drill to prevent slippage. Always wear appropriate eye protection and secure the workpiece before drilling. Do not exceed the recommended RPM range for the workpiece material and bit diameter.