How friction drilling works
Friction drilling what is it?
Friction drilling, Form drilling or Flow drilling is a manufacturing method which uses the original parent material to locally increase material thickness, this extra thickness can then be used to create a threaded connection by using a roll form tap. Friction drilling works in steel, stainless steel, copper and aluminium with thickness’ ranging from 1.0mm to 10.0mm. Standard metric and imperial thread sizes can be catered for.
How friction drilling works
The friction drill meets the material using relatively high axial pressure and rotational speed (approximately 2000 rpm). Frictional heat is generated making the material soft and malleable enough to be formed and perforated. As the friction drill pushes into the material, some of the displaced material forms a collar around the upper surface of the workpiece. The rest of the material forms a bushing in the lower surface of the workpiece. All this happens in a matter of seconds. The resulting collar and bushing can be up to 3 times the original material thickness. With friction drilling the diameter of the bush is accurately determined by the cylindrical part of the friction drill. The secondary step is tapping which is recommended to be completed by a roll form tap (fluteless tap), this rolls the thread creating a chip less and strong connection, approximately 30% stronger than using a cutting tap.
How is the process a suitable alternative to rivet nuts, welded nuts and threaded inserts?
The process is reliable and does not result in the slipping/spinning which occur with rivet nuts. The formed bush is remarkably strong when threaded, it can provide a high torque with high pull out strength connection. Friction drilling has the other main advantage over press nuts and weld nuts that it can be completed blind or in tight profiles, saving time for the production. The process can be completed on standard equipment such as pillar drills or vertical machining centres, this makes it easy to automate reducing production times further.
Friction drill tooling by Flowdrill is
- Capable of strong treaded connections
- Capable of drilling steel, stainless steel, copper, aluminium and brass
- Capable of drilling 1.0 to 10.0 mm material thickness
- Capable of drilling up to 10,000 holes in mild steel and 5,000 holes in stainless steel
- Environmentally friendly, no waste, no single fasteners, and recyclable
