What some people in the lorry sector have been doing for ten years as ‘frame straightening’ with their old Alesco A1000 has remained completely undiscovered in the industry.

It all started with a misunderstanding: that using the A1100 / A4000 induction heaters from Alesco should achieve the same temperature and therefore the same annealing colour on the surface as classic flame straightening. And that is not the case! With the high, direct penetration depth of 17 mm, the inductor can simply be slowly brushed over sheets up to approx. 15 mm thick. All you see is a ‘dark red glow’ – but that’s enough.

And even in the case of indirect heating with sheet thicknesses of 40 mm and more, you have the speed advantage, although the temperatures on the surface are nowhere near as high as with the flame. It should also be mentioned in passing that without the oxidising effect of the flame, the surface will not carburise.

The second major advantage: less energy applied to the material also means less cooling time!

In one application in Sweden, 120 mm thick sheets are straightened with the devices, but this requires a lot of fiddling around in the process.