# Why is gauge thickness different for different metals? **URL:** \ **Category:** Factual Questions\ **Created:** [October 21, 2012, 8:18am UTC](https://boards.straightdope.com/t/why-is-gauge-thickness-different-for-different-metals/638399 "2012-10-21T08:18:39Z")\ **Posts on this page:** 2\ **Page:** 2
**Author:** ![Battle\_Pope](https://avatars.discourse-cdn.com/v4/letter/b/4bbf92/32.png) [@Battle\_Pope](https://boards.straightdope.com/u/Battle_Pope)\ **Post date:** [October 22, 2012, 12:13am UTC](https://boards.straightdope.com/t/why-is-gauge-thickness-different-for-different-metals/638399/21 "2012-10-22T00:13:04Z")
> [@Daylate](#): > > Question, about gauges, but not sheet metal ones. > > Since the gauge of a shotgun is based on how many lead balls of the same diameter as the shotgun barrel would be required to weigh a pound (except of course for a .410), what term do the Europeans use to describe the size of a shotgun? For instance, what would they call a 20 gauge shotgun? Australia here, but usually by the gauge. 20 gauge, 12 gauge etc. We use metric but still refer to the ‘mile-high’ club as well. 😃 ---
**Author:** ![ZenBeam](https://avatars.discourse-cdn.com/v4/letter/z/3ab097/32.png) [@ZenBeam](https://boards.straightdope.com/u/ZenBeam)\ **Post date:** [October 22, 2012, 1:39am UTC](https://boards.straightdope.com/t/why-is-gauge-thickness-different-for-different-metals/638399/22 "2012-10-22T01:39:17Z")
> [@Jamicat](#): > > 1" = 1g = 1.000 in. > 1/16" = 16g = .0625 in. > It drops up and down about a 0.5 millimeter or a .015" per scale…roughly. > > But, anything over 1/8 =.125 becomes plate, then you ask for 1/8" plate steel or aluminum. > > Also, If you buy 0.040" aluminum…its 0.040" measuring with a micrometer. Which is about the same as 1 MM = 0.0397. Did you even look at the link in the OP? [Previous page](https://boards.straightdope.com/t/why-is-gauge-thickness-different-for-different-metals/638399.md?page=1)