Helical Thread Repair Kits

Chrislynn Repair Kits contain everything needed to complete your repair job except a drill bit. This includes a high-speed steel STI plug tap, a combination installation/tang break off tool, and a generous quantity of inserts, in a length equal to one and a half times the diameter of the insert. These kits are available in metric sizes from M2 to M64, and in American sizes from 2-56 to 1-1/2. Larger 8-Pitch sizes up to 3-1/2 are also available. Pipe Thread, Spark Plug and Left-Hand Thread Kits and Refill Inserts are also available.

The Precision insert system was devised as a simple method of repairing stripped or damaged threads in any metal or valuable parts. Inserts are also used in new products such as die castings or plastics, where excessive stress on threads could cause damage or failure.
Precision inserts are helical coils of diamond shaped 18-8 stainless steel wire which meets or exceeds AMS-7245 specification. Inserts are sized to provide a precisely controlled interference fit in an oversized tapped hole. The tap used for this purpose is the same pitch as the original thread but has a larger diameter. When the insert is installed, the hole is returned to its original size.

Because the insert provides an enlarged bearing area, the restored fastening is stronger than the original. It is also more durable, since the stainless-steel thread is generally tougher than the original material. Precision inserts are corrosion resistant and their 22-microinch or better surface finish provides a smooth running, wear-resistant fastening.

Installation:
The first step in creating a new, stronger thread is cleaning up the original, dam- aged threads. This is done with a standard drill, the size of which is indicated on the Precision package. The hole is then tapped with an oversize (STI)* tap provided in each kit. Kits do not include drills. Drills are available at The Nutty Company. The free diameter of the Precision insert is larger than the new threaded hole, but it is easily “wound” into place with the inserting tool provided. Once in place, the insert tends to spring back into its original diameter, giving it a very strong grip in the hole. Finally, the driving tang is broken off by tapping downward with the end of the inserting tool. If necessary, inserts can be re- moved, using an extracting tool.

Drill... Tap... Insert... Remove Tang... Done.

Helical Thread Kits for Thread Restoration

Professional helical thread repair kits provide comprehensive solutions for restoring damaged or stripped threads in various materials. These specialized kits include precision threaded inserts that create stronger, more durable threads than the original material. Each repair kit contains an installation tool specifically designed for proper insert placement and tension. Thread repair applications extend beyond basic maintenance to include cast iron engine blocks, aluminum components, and steel assemblies where original threads have failed. The helical design of these inserts distributes load evenly across multiple threads, often creating connections stronger than the original bolt specifications. Professional mechanics and machinists rely on these kits for critical repairs where thread integrity is essential. Whether restoring vintage equipment or repairing modern machinery, thread repair kits offer reliable solutions that extend component life. The versatility of these systems makes them indispensable for automotive, aerospace, and industrial applications requiring precision thread restoration.

FAQ

What is included in a helical thread repair kit?

A complete thread repair kit includes helical threaded inserts, a specialized installation tool, drill bits, and tapping tools. Most kits contain multiple insert sizes and detailed instructions for proper thread repair procedures. Quality repair kit packages ensure you have everything needed to restore damaged threads in materials like cast iron and steel components requiring bolt connections.

How do I use a thread repair insert kit to fix damaged threads?

Using thread repair kits involves drilling out damaged threads, tapping new threads, and installing threaded inserts with the provided installation tool. The process works effectively on cast iron, aluminum, and steel materials. Each repair kit includes step-by-step instructions for proper thread repair, ensuring the restored bolt connection exceeds original strength specifications and performance requirements.

Are your helical thread repair kits compatible with both metric and standard sizes?

Yes, our thread repair kits accommodate both metric and standard thread specifications. Each repair kit includes threaded inserts and installation tool configurations for various nut & bolt sizes. These kits work effectively across different thread pitches and materials including cast iron applications. Professional thread repair solutions ensure compatibility with both measurement systems for comprehensive coverage.

Can I reuse the inserts from a thread repair insert kit?

Threaded inserts from thread repair kits are designed for permanent installation and typically cannot be reused. Once installed with the installation tool, the helical design locks into position for lasting thread repair. While the bolt can be removed repeatedly, the insert remains permanently fixed in cast iron or other materials, providing reliable long-term performance.