Hertel 77428589 Reduced Shank Drill Bit 33/64 in Hss

Product Description

The HERTEL 77428589 is a reduced shank drill bit machined from high-speed steel (HSS) with an oxide finish. It features a 33/64-inch (0.5156 inch decimal) cutting diameter paired with a 1/2-inch Weldon flat shank, allowing it to seat securely in set-screw-style tool holders on drill presses and milling machines. The 118-degree standard point angle makes it suitable for general-purpose drilling in low- and medium-tensile-strength materials. Overall length is 6 inches with a 3-inch flute length, and the right-hand spiral flutes are ground in a regular helix for consistent chip evacuation. Machinists and maintenance technicians keep this bit on hand for production and repair work where a reduced shank is required to fit standard 1/2-inch holders.

This drill bit is intended for drilling low- and medium-tensile-strength materials, including mild steel, aluminum, brass, plastics, and similar workpiece materials. The Weldon flat shank with three flats prevents slipping under torque loads, making it well suited for use in milling machine spindles, drill press chucks fitted for Weldon tooling, and portable magnetic drills. It is commonly used in fabrication shops, maintenance departments, and light manufacturing environments where consistent hole size and repeatability are required.

Key Features

• Reduced shank design: 33/64-inch cutting diameter on a 1/2-inch Weldon flat shank for use in standard 1/2-inch tool holders
• High-speed steel construction for durability across repeated use in low- and medium-tensile-strength materials
• 118-degree standard point angle for general-purpose drilling without specialized geometry
• Oxide finish helps resist corrosion and reduces friction during cutting
• Three-flat Weldon shank prevents rotation and slippage under load
• Right-hand spiral flutes in regular helix for efficient chip removal

Compatibility

Designed for use in drill presses, milling machines, and magnetic drills fitted with 1/2-inch Weldon-style tool holders; suitable for drilling low- and medium-tensile-strength materials.

Installation Notes

A licensed machinist or qualified maintenance technician should install and operate this bit. Always power down and lock out the machine before securing or removing the bit in the tool holder. Tighten all set screws against the Weldon flats to manufacturer specifications before initiating a cut. Inspect the cutting edges for wear or damage before each use, and never exceed the rated drilling depth of 3 inches.