Hertel 77428654 Reduced Shank Drill Bit 39/64 in Hss

Product Description

The HERTEL 77428654 is a reduced shank twist drill bit designed for drilling into low and medium tensile strength materials. The bit measures 39/64 inch (0.6094 inch decimal) in cutting diameter with a 1/2 inch Weldon flat shank, allowing it to seat securely in compatible chucks and holders. Built from high-speed steel with an oxide finish, it offers adequate hardness and surface protection for general-purpose metalworking. Overall length is 6 inches with a 3 inch spiral flute length, providing sufficient chip clearance in moderate-depth holes. The 118-degree standard point angle suits a wide range of common materials. This bit is installed by machinists, maintenance technicians, and metalworking tradespeople.

This drill bit is suited for use in drill presses, milling machines, and hand-held power tools equipped with a 1/2 inch chuck or Weldon-style tool holder. It is intended for right-hand cutting operations in low and medium tensile strength materials such as mild steel, aluminum, and similar workpieces. The 3-flat Weldon shank design prevents slippage under torque, making it a practical choice for production drilling environments where consistent positioning is required. Maximum drilling depth matches the 3 inch flute length.

Key Features

• 39/64 inch cutting diameter (0.6094 inch decimal) with a 1/2 inch reduced Weldon flat shank
• 118-degree standard point angle for general-purpose drilling in common metals
• High-speed steel construction for durability across repeated use cycles
• Oxide finish provides surface protection and reduces friction during cutting
• 3-flat Weldon shank with 3 flats resists rotational slippage in holder
• Right-hand spiral flute with regular helix for efficient chip evacuation

Compatibility

Designed for use with 1/2 inch Weldon-style tool holders and compatible chucks in drill press or machine tool applications. Suited for drilling low and medium tensile strength materials.

Installation Notes

Installation should be performed by a qualified machinist or maintenance technician familiar with drill press and machine tool operation. Secure the Weldon shank fully into the tool holder and tighten set screws against the flats before operation. Ensure the workpiece is properly clamped before beginning the cut. Follow applicable shop safety procedures and machine manufacturer guidelines when setting spindle speed and feed rate.