Hertel 77429041 Reduced Shank Drill Bit 1-5/16 in Hss

Product Description

The HERTEL 77429041 is a reduced shank twist drill bit designed for drilling through low and medium tensile strength materials using standard drill press or milling machine setups. The cutting diameter measures 1-5/16 inches with a 1/2-inch Weldon flat shank, allowing it to seat securely in compatible chucks and holders without slipping under torque. The 118-degree standard point angle suits general-purpose hole-making in mild steel, aluminum, and similar workpiece materials. Built from high-speed steel with an oxide finish, this bit offers adequate heat resistance and corrosion protection for production and maintenance drilling applications. Installation is handled by machinists, tool-and-die professionals, and industrial maintenance mechanics.

This bit is suited for production drilling environments where a large-diameter hole is required in a single pass without the need for a full-shank design. The 1/2-inch reduced shank allows use in standard half-inch chucks and Weldon-style toolholders, making it compatible with a wide range of drill press and milling machine spindles. The right-hand spiral flute configuration clears chips efficiently on through-hole and blind-hole operations in low and medium tensile strength ferrous and non-ferrous materials. No coolant-through capability is present, so external coolant or cutting fluid application is recommended for extended run cycles.

Key Features

• 1-5/16-inch cutting diameter with a 1/2-inch Weldon flat shank for secure chuck engagement
• 118-degree standard point angle for general-purpose drilling in mild metals and similar materials
• High-speed steel construction with oxide finish for heat and corrosion resistance
• Right-hand, regular spiral flute design promotes effective chip evacuation
• 3-inch flute length provides a maximum drilling depth of 3 inches
• Three Weldon flats on shank prevent rotation under load in compatible toolholders

Compatibility

Designed for use with 1/2-inch Weldon-style toolholders and drill chucks rated for the 1/2-inch shank diameter. Intended for drilling low and medium tensile strength materials as stated by the manufacturer.

Installation Notes

Installation should be performed by qualified machinists or maintenance mechanics familiar with rotary cutting tool safety. Ensure the machine spindle is fully powered down and locked out before inserting or removing the bit from the toolholder. Seat the Weldon flat fully against the set screw in the holder and tighten to the toolholder manufacturer's specification before operation. Apply an appropriate cutting fluid externally during use, as this bit does not support internal coolant delivery.