Heli-coil 3724-16 Thread Insert Hand Tool 1-8 Unc

Product Description

The HELI-COIL 3724-16 is a hand installation tool designed for driving wire thread inserts into pre-tapped holes. Built around a Type III Threaded Mandrel configuration, it engages the insert tang and winds the coil into the threaded bore with controlled, consistent torque applied by hand. The tool measures 4-7/8 inches in overall length with a 4-1/2 inch spinner diameter, giving technicians a solid grip surface for high-torque manual installation. Compatible with both free-running and locking insert styles, it covers the full range of standard HELI-COIL insert types used in production repair and field service work.

This tool is used wherever a 1-8 UNC thread insert requires hand installation - common applications include heavy equipment repair, structural fastener restoration, and field service on large-diameter tapped bores. Machinists, maintenance technicians, and field service mechanics reach for this tool when power drivers are not practical or when installation torque must be controlled manually. The 1-8 thread size designation indicates a 1-inch nominal diameter with 8 threads per inch, placing this tool firmly in the heavy-duty fastener repair category.

Key Features

• Type III Threaded Mandrel drives inserts with positive thread engagement for consistent seating depth
• Compatible with both free-running and locking wire thread insert styles
• 1-8 UNC thread standard - 1-inch nominal diameter, 8 threads per inch
• 4-7/8 inch overall length provides clearance in most access scenarios
• 4-1/2 inch spinner diameter delivers ample leverage for hand torque on large-bore inserts
• Hand-operated design suits field repair where power tooling is not available

Compatibility

Designed for use with free-running and locking wire thread inserts in 1-8 UNC tapped holes. Verify insert manufacturer specifications to confirm mandrel compatibility before installation.

Installation Notes

Installation of wire thread inserts should be performed by a qualified machinist or maintenance technician familiar with thread repair procedures. Ensure the tapped hole is clean and free of debris before driving the insert. Apply steady, even hand pressure on the spinner to seat the insert flush with or just below the host material surface. After installation, remove the drive tang using the appropriate tang break-off tool per the insert manufacturer's instructions.