For thin-walled sheets or tubes, when internal threads are required, the conventional method is to use rivet nuts. However, this approach not only adds extra processing steps and reduces efficiency, but also often leads to loosening issues due to weak welding or riveting.
Thermal friction drilling technology was developed to address these challenges.
Thermal friction drilling for Square tube
Origin of Thermal Friction Drilling
Thermal friction drilling technology originated in Germany. It enables threading on thin materials within just a few seconds, without the need for additional processes.
Working Principle
The principle of thermal friction drilling is based on heat generation through high-speed rotation of a specialized conical tool.
When the rotating tool contacts the metal surface, it instantly generates high temperatures of approximately 600–800°C, causing the material to soften. Even at rotational speeds of 1500–3000 RPM, the tool maintains high hardness and excellent wear resistance.
Flow drill demo
As the tool continues to rotate and apply downward pressure, the softened material is displaced and extruded along the hole axis, forming a bushing (sleeve). This process creates a wall thickness up to three times thicker than the original material.
The entire process is completed within 2–6 seconds.
Key Advantages of Thermal Friction Drilling
Thermal friction drilling is a chipless forming process, which significantly simplifies production steps and improves material utilization.
After the friction-induced heating and subsequent air cooling, the material undergoes an effect similar to normalizing heat treatment, enhancing its mechanical properties.
Importantly, this process does not damage the base material structure. The formed bushing exhibits:
High strength
Excellent torque resistance
Superior thread engagement capability
This allows for direct, high-quality tapping without additional reinforcement.
Flow drill and tapping machine
Material Compatibility
Thermal friction drilling is compatible with a wide range of thin-walled metals, including:
Mild steel
Stainless steel
Low-carbon steel
Aluminum
Copper
Brass
Bronze
Titanium alloys
It is also suitable for plated or coated materials, making it highly versatile across industries.
Conclusion
Thermal friction drilling is an advanced, efficient, and highly reliable metal forming technology. With its ability to eliminate secondary operations, improve thread strength, and enhance production efficiency, it represents a valuable solution for modern manufacturing.
