Thread repair tools

Discover our range of high-quality RUKO thread repair tools for repairing damaged internal threads in metal.

Thread repair tools are used wherever threads are stripped, worn or can no longer bear a load. This allows components to be repaired cost-effectively, rather than having to replace them entirely.

In professional applications, RUKO thread repair systems ensure a precise thread fit, reduce downtime and enable reproducible repair processes. Depending on the application, optimally coordinated components are used – twist drills, single-cut taps, fitting tools, thread inserts and tap breakers.

Precise manufacturing and systematically combined tools result in robust threads with a high level of operational reliability – even in demanding applications. At the same time, the repair of existing components reduces material consumption and leads to long-term cost savings.

Thread repair tools are used to prepare a damaged internal thread so that a suitable thread insert can be securely fitted into it. The original thread is reamed out and provided with a new receiving thread.

Typical procedure:
• Reaming out the damaged thread
• Cutting a receiving thread
• Inserting a thread insert

This creates a new, robust internal thread with the original nominal diameter. In many cases, thread strength is improved, particularly with softer materials.

You can also find detailed step-by-step instructions for thread repair in our blog article on thread repair.

We also demonstrate how to use the thread repair tools in a short YouTube video.

In practice, damaged threads are often caused by mechanical or thermal stress. Typical causes include:

• Overtightening or excessive tightening torque

• Improper loosening of seized screws

• Corrosion or contamination within the thread 

• Insufficient strength of the base material (e.g. aluminium)

Depending on the nature of the damage, a targeted thread repair can fully restore functionality.

Thread repair tools are used in numerous industrial sectors, particularly where components need to be maintained cost-effectively and function-critical connections must be reliably restored.

Metalworking
• Repair of damaged internal threads in components
• Re-machining of threads following mechanical stress
• Restoration of functionally critical screw connections
The focus is on the precise restoration of thread functionality and the extension of component service life.

Machinery and Plant Engineering
• Repair of threads in machine components
• Repair of threads in components that are difficult to replace
• Maintenance and servicing of plant

This helps minimize downtime and reduce repair costs.

Maintenance and Servicing
• Repair of threads whilst the equipment is in operation
• Rectification of damaged screw connections
• Reinforcement of threads in soft materials

Quick and reliable solutions are crucial, particularly in maintenance. Thread repair tools are therefore a key component of efficient repair and maintenance processes.

A thread repair system consists of several precisely matched components which, when used together, enable the reliable and durable restoration of internal threads.

Twist drill

The twist drill is used to ream the damaged thread to the desired diameter and to prepare the bore for the subsequent cutting of the mounting thread.

Typical characteristics and functions:

• Precise reaming of damaged threads
• Preparation for the receiving thread
• High dimensional accuracy

This creates the necessary foundation for a precise-fitting and robust thread repair.

Single-cut taps

Single-cut taps are used to cut the receiving thread for the thread insert and are specifically designed to meet the requirements of thread repair.

Typical features and functions:
• Precise cutting of the receiving thread for the thread insert
• Precise guidance of the thread insert
• Adaptation to standard threads

This creates a precisely fitting receiving thread for the subsequent thread insert.

Fitting tools

Fitting tools are used to screw the thread insert into the prepared thread in a controlled manner.

Typical features and functions:
• Secure positioning of the insert
• Uniform screwing in
• Prevention of damage

They ensure a clean and repeatable installation.

Thread inserts

Thread inserts are the key component of the repair. They are inserted into the newly cut receiving thread and form the new internal thread.

Typical characteristics:
• High load-bearing capacity
• Corrosion-resistant
• Precisely fitting thread geometry

They enable the original nominal diameter to be restored.

Pin breakers

After installation, the drive pin of the thread insert is removed.

Typical characteristics and functions:
• Breaking off the pin after installation
• Clearing the thread
• Preparing for the insertion of the screw

It is an essential part of the repair process.

Careful coordination of the individual components ensures a precise and durable thread repair. Thread repair tools are available as individual parts as well as complete repair kits.

The choice of the appropriate system depends on several technical factors.

Thread size and pitch
The repair system must match the original thread exactly.
• Metric threads (e.g. M6, M8, M10)
• Ensure the pitch is correct

This is the only way to restore the original function.

Application and load
Requirements for thread strength vary depending on the application.
• Static connections
• Dynamic loads
• High-stress bolted connections

Making the correct choice increases the service life of the connection and improves operational safety.

Slightly damaged or contaminated threads can often be repaired by re-cutting them with a tap.

However, in the case of severely worn, stripped or deformed threads, this is not sufficient, as the original geometry of the thread cannot be restored.

In such cases, a thread repair system must be used to create a new, load-bearing internal thread.

The following points are crucial for reliable and precise thread repair:

• Drill the centre hole to the exact specified diameter
• Use a suitable cutting tap
• Position the tap exactly at right angles and cut the thread
• Use suitable cutting oils to reduce friction and wear
• Screw the threaded insert in evenly and without applying any tension
• Remove the drive pin cleanly

These steps ensure a high degree of fit accuracy and a thread connection capable of withstanding long-term loads.