Asahi US-638 Thermostats

Asahi US-638 low-profile thermostats are only 5.1mm thick and so are the thinnest in the Asahi range.  They are designed using the same ultra-reliable 1/2″disc bimetal technology used in Asahi’s main product lines and can readily switch up to 100,000 cycles at 4A/250VAC.

The US-638 thermostat is available with calibrations from 30°C to 100°C in steps of 5 degrees.  The set-point tolerance is typically ±5K with a thermal differential of 10K±5K depending on the set-point calibration.  Slightly tighter tolerances and differentials are also available depending on the application and calibration required, please contact us to discuss.

The Asahi US-638 thermal control has been designed with high-volume applications in mind such as car-seat heaters and medical heater pads.  Their production is highly automated giving the reliability and cost-savings required in these competitive markets.


  • Car seat heaters
  • Small household appliances
  • Personal care products
  • Flexible heater elements
  • Electric heating control


  • 10K±5K differential ensures precision control
  • Reliable snap-action contact operation
  • Calibrations from 30°C to 100°C
  • 4A/250VAC 100k cycle approval
Low profile thermostat Cost effective. 5.1mm thick thermostat