flow drilling

Threading for Thin-Walled
Tube Applications

Flow drilling and tapping provides a highly effective way to create strong, reliable threaded connections in thin-walled tube and hollow sections. By forming threads directly within the parent material, the process eliminates the need for welded bosses, threaded inserts, or additional components, helping to reduce manufacturing costs, improve consistency, and streamline assembly.

Suitable for steel, stainless steel, aluminium, copper and other alloys, flow drilling is widely used across automotive, industrial, construction and engineering applications where conventional threading methods are limited by material thickness. The result is a clean, durable fastening solution that delivers excellent strength and long-term performance.

What is Flow Drilling?

Flow drilling is a thermal forming process that uses a high-speed rotating tool to generate heat through friction. As the tool penetrates the material, the displaced material is formed into an elongated bush around the hole.

The resulting bush typically provides up to 300% greater depth than the original wall thickness, creating sufficient material for threaded connections that would otherwise be impossible or unreliable using the parent material alone.

Following the flow drilling process, threads can be tapped directly into the formed bush to create a strong and durable fixing point.

Material Compatibility

MILD STEEL

Well suited to flow drilling applications, providing strong threaded connections and excellent durability across a wide range of industrial uses.

STAINLESS STEEL

Flow drilling creates clean, reliable threaded bushes in stainless steel, making it ideal for demanding environments where corrosion resistance is essential.

ALUMINIUM

A lightweight material that responds well to flow drilling, allowing secure threaded connections without the need for additional inserts or fixings.

COPPER

Flow drilling can be used to create robust threaded features in copper components while maintaining material integrity and assembly efficiency.

COPPER Alloys

Suitable copper alloys can be flow drilled and tapped to produce strong, reliable threads for specialist fluid transfer and engineering applications.

Advantages of
Flow Drilling

Benefits over conventional fastening and joining methods:
  • No access required to the rear of the workpiece for attaching a secondary nut
  • Creates a strong threaded connection within the parent material
  • Suitable for a wide range of thread diameters and material thicknesses
  • Eliminates the need for weld nuts, rivet nuts and inserts
  • Reduces component costs and assembly time
  • Creates a clean, reliable and repeatable fastening solution
  • Supports higher loading due to the homogeneous material structure
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