Heli-coil 7751-12 Thread Insert Tool M12 X 1.75 Prewinder

Product Description

The HELI-COIL 7751-12 is a hand installation tool designed for installing thread inserts into M12 x 1.75 metric coarse threaded holes. It uses a Type II prewinder mechanism that winds the insert onto the mandrel before driving it into the prepared bore, ensuring consistent installation depth and thread alignment. The tool is built for bench and field use by machinists, mechanics, and maintenance technicians working on thread repair or new assembly applications. With a prewinder body diameter of 0.875 inches and an overall prewinder length of 5.5 inches, it delivers controlled torque engagement without requiring power tools.

This tool is suited for metric coarse thread insert installations in automotive, industrial, and general mechanical repair environments. It is commonly used when restoring stripped threads in aluminum, cast iron, or steel components where a coil-type thread insert is the specified repair method. The hand-operated design gives the technician tactile feedback during installation, reducing the risk of cross-threading or over-driving the insert.

Key Features

• Prewinder Type II design winds insert onto mandrel before installation for controlled, accurate seating
• Sized for M12 x 1.75 metric coarse thread inserts
• Prewinder body diameter of 0.875 inches for compact access in tight bores
• Spinner diameter of 3.71875 inches provides comfortable manual torque application
• Prewinder length of 5.5 inches accommodates standard insert depths
• Hand-operated for use without power tools, suitable for field repair and bench work

Compatibility

Designed for use with M12 x 1.75 metric coarse thread inserts. Confirm insert manufacturer specifications to verify tool-to-insert compatibility before installation.

Installation Notes

Thread insert installation should be performed by a qualified machinist or mechanic familiar with thread repair procedures. The receiving hole must be drilled and tapped to the correct insert-tap specification before the tool is used. Do not use power drivers with this hand tool. Ensure the workpiece is secured before beginning installation to prevent movement during insert seating.