Annealing brass and bronze tubing prior to bending to form handrails

Objective

Annealing brass and bronze tubing for bending in a mandrel bender to form handrails 

End Product

Handrails

Equipment

• Ambrell 6 kW induction heating system, equipped with a remote workhead containing two 0.5µF capacitors for a total of 0.25µF

• An induction heating coil designed and developed specifically for this application. 

Materials

• Brass tubes 1.5” (38.1mm) and 2” (50.8mm) diameter with 0.065” (1.65mm) wall thickness

• Bronze tubes 1.5” (38.1mm) and 2” (50.8mm) diameter with 0.100” (2.54mm) wall thickness 

Temperature

1000 ºF (538 ºC)

Frequency

228 kHz

Testing

A twelve turn helical coil is used to heat an 8” (20.3cm) area 3” (7.6cm) above the end of the tube. Each of the four tubes require a different heat cycle and time to reach the required temperature. 

Benefits

Induction heating provides:

• High efficiency, low energy costs

• Precise and controllable placement of heat

• Hands-free heating that involves no operator skill for manufacturing

• Even distribution of heating, eliminating fractures during bending 

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