Heli-coil 5521-24 Thread Repair Kit 1-1/2-6 Unc

Product Description

The HELI-COIL 5521-24 is a threaded insert thread repair kit designed to restore stripped or damaged 1-1/2-6 UNC internal threads to full load-bearing strength. The kit includes a drill, tap, installation tool, tang removal tool, and four helical coil inserts at 2.25 inches in length. It is used across industrial maintenance, heavy equipment, and machinery repair applications where large-diameter fastener threads have been compromised. Machinists, millwrights, and maintenance technicians install this kit as a permanent repair solution without replacing the entire parent component.

This kit is suited for 1-1/2-6 UNC thread repair in ferrous and non-ferrous base materials including steel, cast iron, and aluminum. The 2.25-inch insert length accommodates deep-thread engagement requirements common in high-load bolted joints. With all tooling included, the kit supports single-setup repairs in the field or on the shop floor. Four inserts are included, allowing for multiple repair locations per kit.

Key Features

• Repairs 1-1/2-6 UNC threads with a 2.25-inch helical insert
• Complete kit includes drill, tap, installation tool, and tang removal tool
• Four inserts included per kit for multiple repair sites
• UNC thread standard for compatibility with standard inch-series fasteners
• Installation tool part number 3724-24, tap part number 8187-24, insert package part number K1185-24

Compatibility

Designed as an OEM-style thread repair solution for any parent material requiring restoration of 1-1/2-6 UNC internal threads to standard specification.

Installation Notes

Installation is typically performed by a machinist or qualified maintenance technician. The damaged bore must be drilled to the specified tap drill size before tapping and insert installation. Follow the included tooling sequence: drill, tap, install insert, then remove the tang using the provided tang removal tool. Ensure the workpiece is secured and all rotational equipment is de-energized or de-pressurized before beginning thread repair work.