# How much could I safely heat a content-less cast-iron pan?

To which temperature could I safely heat my cast-iron pan on the stove, without any contents? I don't want to re-season it afterwards. Afterwards, I'd just let the pan cool off in room temperature. The base is ~0.5 cm thick.

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If it is completely empty, you probably can't reach dangerous temperatures with your stove. The iron itself melts at 1500°C. The seasoning can be burnt off at much lower temperatures, a self-cleaning cycle in the oven is enough for it (500°C). I have taken an iron pan to above 400°C without damaging the seasoning. (I don't know exactly how high it was, my thermometer doesn't go above 400°C). This was on an induction stove set at maximum, I doubt that any other kind of stove can produce such temperatures.

Edit I just heard an example showing that you can take a pan on a resistive stove to above 500°C with prolonged heating, so you should be measuring it if you plan to go that high. (and if you have a thermometer in this range, you can post your findings to further limit the range of 400° to 500°C, because I'm curious).

But if you say "no contents", be careful that it is actually just the pan. You cannot oil it, because the self-ignition temperature (of flash point) of vegetable oil is low, Wikipedia gives it at 327°C. It could just smoke terribly and throw a spark or two when you reach it, but it can also flame up and then you are holding a small brand in your hand.

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I bring my cast-iron to 500C regularly for steaks. I preheat the skillet in a 525F oven (as hot as it will go), then I put it on my hottest burner (electric coil stove) for 5 minutes. Checked with an IR thermometer, that does in fact get the pan to 500C. Once I answered the phone and let it go for longer than 5 minutes (8 maybe?). It made an audible poof and burnt all the seasoning in the bottom of the pan to ash. So, I'd say 500C for a short amount of time is your absolute upper limit if you want to preserve your seasoning.

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Over 720°C you run the risk of changing the hardness and other properties. A domestic stove should not be able to get anywhere near this temperature

This is best done outside on a standalone gas burner. Do not have any liquids near by

Where are you going to get a suitable thermometer from :-)

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My planned range was up to 250°C, but I'll see what I can find at the local faculty for material physics :) – user4697 Jan 8 '12 at 19:56
@TimN: 250°C/482°F? I heat mine hotter than that for normal cooking applications. That temperature is only a concern for Teflon and similar; iron, stainless, even aluminum should be fine. – derobert Jan 9 '12 at 16:03
@derobert I just wanted to be careful since I normally don't cook without pan contents, and maybe it could hurt the seasoning. – user4697 Jan 9 '12 at 16:54
@TimN: It's perfectly normal to preheat pans before adding food, and to preheat them completely empty (except for Teflon, where you add the oil cold, to make sure that the oil smoking gives you warning before the Teflon overheats). – derobert Jan 9 '12 at 17:25
Thanks @derobert! – user4697 Jan 9 '12 at 17:26