Hertel 77428779 Reduced Shank Drill Bit 51/64 in Hss

Product Description

The HERTEL 77428779 is a reduced shank drill bit designed for drilling into low and medium tensile strength materials. It features a 51/64 inch (0.7969 inch decimal) cutting diameter paired with a 1/2 inch Weldon flat shank, allowing it to seat securely in standard chucks and holders. The bit is manufactured from high-speed steel with an oxide finish for basic lubricity and corrosion resistance. With a 118-degree standard point angle and right-hand spiral flute geometry, it produces clean, consistent entry points in ferrous and non-ferrous materials. Machinists, maintenance mechanics, and tool-room technicians are the primary installers of this bit in drill press and milling machine setups.

This bit is suited for production and maintenance drilling applications in metalworking environments, including fabrication shops, maintenance facilities, and light manufacturing. The 1/2 inch Weldon shank with three flats prevents slipping under torque, making it appropriate for use in driven tool holders on drill presses, knee mills, and similar equipment. Maximum drilling depth is 3 inches, which aligns with the 3-inch flute length. Target workpiece materials include low and medium tensile strength metals and similar materials within that hardness range.

Key Features

• 51/64 inch cutting diameter (0.7969 inch decimal) for precise bore sizing
• 1/2 inch Weldon flat shank with three flats resists rotation in the holder
• 118-degree standard point angle for general-purpose drilling
• High-speed steel construction handles a broad range of metalworking applications
• Oxide finish provides basic surface protection and lubricity
• Right-hand cut with regular spiral flutes for efficient chip evacuation

Compatibility

Designed as an OEM-style replacement or production-use drill bit for tool holders and chucks accepting a 1/2 inch Weldon flat shank, suitable for use in drill presses, milling machines, and similar driven equipment.

Installation Notes

Installation should be performed by qualified machinists or maintenance personnel familiar with rotating tooling and drill press or milling machine operation. Secure the Weldon shank fully in the tool holder and tighten set screws against the flats before operation. Always power down and lock out the machine before changing or inspecting tooling. Ensure the workpiece is firmly clamped and use appropriate cutting fluid recommendations for the workpiece material, noting this bit is rated for dry operation with no internal coolant channel.