# water in a hot frying pan **URL:** \ **Category:** Factual Questions\ **Created:** [May 31, 2003, 7:18pm UTC](https://boards.straightdope.com/t/water-in-a-hot-frying-pan/178813 "2003-05-31T19:18:14Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![Jitterbug\_Boy](https://avatars.discourse-cdn.com/v4/letter/j/c57346/32.png) [@Jitterbug\_Boy](https://boards.straightdope.com/u/Jitterbug_Boy)\ **Post date:** [May 31, 2003, 7:18pm UTC](https://boards.straightdope.com/t/water-in-a-hot-frying-pan/178813/1 "2003-05-31T19:18:14Z")
Will putting water in the hot frying pan damage the pan, or is that something mom invented to keep us from having fun? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [May 31, 2003, 9:40pm UTC](https://boards.straightdope.com/t/water-in-a-hot-frying-pan/178813/2 "2003-05-31T21:40:15Z")
If it’s a cast iron pan, it could easily crack it. Lighter aluminum pans won’t crack, usually, but can be severely and permanently warped from this. A few drops won’t do any damamge, and if the pan is hot enough, you can observe the Leidenfrost effect: the drops will skitter about on the surface for a long time, because a thin lyaer of steam between the drop and the pan’s surface insulates it and keeps it from boiling away quickly. ---
**Author:** ![Jitterbug\_Boy](https://avatars.discourse-cdn.com/v4/letter/j/c57346/32.png) [@Jitterbug\_Boy](https://boards.straightdope.com/u/Jitterbug_Boy)\ **Post date:** [June 1, 2003, 12:15am UTC](https://boards.straightdope.com/t/water-in-a-hot-frying-pan/178813/3 "2003-06-01T00:15:33Z")
Thanks; that answers our question. Is it, do you know, the rapid temperature change, or is it the temperature difference from one spot on the pan to another? In other words, would thrusting the whole thing into cold water at once, like they do with swords, prevent the damage, compared to pouring water on one spot while another remains hot? Why do they do that with swords, anyway? ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [June 1, 2003, 12:26am UTC](https://boards.straightdope.com/t/water-in-a-hot-frying-pan/178813/4 "2003-06-01T00:26:33Z")
Cast iron is a much more brittle than the type of steel used for swords. So the rapid change in temperature can crack pans made from it. It depends too, on how hot the pan is. It’s much more likely to crack if the temperature is very high, since the change in expansion is much greater. Stainless steel pans won’t crack, and nor will they warp as much as aluminum ones. The process you’re desbribing with swords and other tools made from steel is called _tempering_. The process involves heating the article to be treated to red-hot temperature, and then _quenching_ it, or plunging it quickly into cold water. This rapid cooling prevents the formation of large-grained crystals in the steel, which cause the steel to be softer. It’s quite an art form, as the temperature must be just right depending on the precise properties you want your steel to have, whether it’s hardness, springiness, or what have you. ---
**Author:** ![Trigonal\_Planar](https://avatars.discourse-cdn.com/v4/letter/t/0ea827/32.png) [@Trigonal\_Planar](https://boards.straightdope.com/u/Trigonal_Planar)\ **Post date:** [June 1, 2003, 1:25am UTC](https://boards.straightdope.com/t/water-in-a-hot-frying-pan/178813/5 "2003-06-01T01:25:57Z")
Q.E.D.: I always thought tempering seals the outer surface of a material which prevents dislocations from moving to the surface. This of course strenghtens the material by preventing surface-crack formation.