this was asked on another automotive forum but no respond
See few of these around, these induction heating nut loosing gadgets. Anyone used them professionally in their shop? worth to get ? these seems to be home use ones not sure how good they are. Don't want to store oxy-acetylene at home and the oxygen-mapp gas ones are never strong enough. tried welding on nuts to broken bolt trick 50% works and pain when doing it under car.

OTC 6650
Mini-Ductor
BoltBusters
Fluxeon

I think miller have one for pipe heating for 25K which is out of range for avg Joes