Preheating between 482 to 649°C is recommended before heating parts above 704°C if the parts have been previously hardened to 35 Rc / 345 HV 10 or greater or if the geometry of the part may produce excessive stresses during heat up.
When preheating parts above 300°C, a protective atmosphere is recommended to reduce surface oxidation. Air, without a protective atmosphere, is acceptable when preheating parts below 300°C.
Pre Heating Furnaces by Therelek
Chamber Furnace
![](https://www.therelek.com/wp-content/uploads/2017/10/chamber-furnace-300x300.jpg)
Therelek’s chamber furnace can operate up to 1800°C. These furnaces are usually rugged, refractory based construction
![](https://www.therelek.com/wp-content/uploads/2017/10/chamber-furnace-300x300.jpg)
Continuous Mesh Belt Furnace
![](https://www.therelek.com/wp-content/uploads/2020/05/continuous-mesh-belt-furnace-therelek-featured-300x300.jpg)
A multi-zone control environment is present in a continuous high-temperature furnace, often with a single pre-heating zone.
![](https://www.therelek.com/wp-content/uploads/2020/05/continuous-mesh-belt-furnace-therelek-featured-300x300.jpg)
Bogie Hearth Furnace
![](https://www.therelek.com/wp-content/uploads/2017/10/bogie-hearh-furnace-300x300.jpg)
Our standard bogie hearth furnace goes up to 1500°C, however, we make custom designed furnaces for any special requirements.
![](https://www.therelek.com/wp-content/uploads/2017/10/bogie-hearh-furnace-300x300.jpg)