Fastening Industry Products

Thread Annealing/Hardening

Induction heating is used to selectively harden, temper or anneal specific areas of bolts/shafts for a large range of products. The component shown in this photograph has had the splines induction hardened and then the thread has been induction annealed so as to prevent the failure that could otherwise occur if the threads were left in a 'brittle' state.

Thread Locking
	Induction heating has been used as the preferred method of heating for curing thread locking and sealing patches on nuts and bolts for many years.  The induction heating method lends itself to both automatic and semi-automatic methods of production. Systems have been supplied for processing  large steel nuts and bolts down to instrument screws and components.

Surface Coating

Induction heating provides the ideal heat source for curing surface coatings because it is a 'cold heat source' i.e. the heating coil does not produce heat, it does however provide a powerful alternating magnetic field and it is the effect of electrical currents produced in the nut or bolt that causes them to heat.

This means that the surface coating is cured from the inside and this allows very rapid curing/drying times for powder or liquid coatings.  Also see our section on Curing/Surface Coatings.

Metal/Plastic Inserts
Induction heating is used to heat metal items for insertion into plastic components.  Applications include audio visual, automotive, domestic, aerospace and communication products. In addition to the male and female threaded components shown here, we also manufacture equipment for plastic to metal bonding such items as coat hangers, brushes and fancy goods.

Bolt Head Forming

This 3-position heating system is for manual load/unload.  The operator places cold bars into the 'pigeon holes' and pneumatic pushers are timed to sequentially eject the hot bars at the correct time/temperature.  

The operator takes the hot bar off the carrier and pushes the next cold bar into the heating coil.  The cyclic work pattern where one bar is just coming up to temperature, one bar is warming up and one bar has just been placed into the work coil, provides a good loading condition for the induction heater.

Here, bars are seen coming out of a tunnel type induction heating coil.  The bars in this photo will be automatically transferred to a press where an eye will be formed on the end of the bar.   One will notice that the heated length, relative to the diameter, is longer than would be associated with head forming but the same type of coil and transfer/delivery system is used in bolt manufacture.