Sheet metal gauge calculation


  #1  
Old 05-04-22, 04:38 AM
T
Member
Thread Starter
Join Date: Jan 2015
Location: USA
Posts: 915
Received 86 Upvotes on 76 Posts
Sheet metal gauge calculation

I needed 24 gauge or thicker sheet metal for a rodent barrier and used two sheets of 30-gauge. The exercise I went through to figure out if doubling 30-gauge sheet metal would work involved converting 24 gauge to mm (.701 for galvanized), then finding the gauge needed to reach it - at least 31 gauge, doubled.

This got me wondering if there's a formula for comparing gauge without having to convert it to something else. Any help would be appreciated.
 

Top Answer

 
05-04-22, 01:08 PM
Norm201's Avatar
Norm201
Norm201 is offline
Member
Join Date: Sep 2013
Location: United States
Posts: 11,568
Received 647 Upvotes on 572 Posts
Yes! Metric!
 
  #2  
Old 05-04-22, 01:08 PM
Norm201's Avatar
Member
Join Date: Sep 2013
Location: United States
Posts: 11,568
Received 647 Upvotes on 572 Posts
Yes! Metric!
 
CircuitBreaker, Marq1 voted this post useful.
  #3  
Old 05-04-22, 05:50 AM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 28,578
Received 1,707 Upvotes on 1,525 Posts
Why use a formula? Just look at any of the MANY charts available online and in books.

 
cwbuff voted this post useful.
  #4  
Old 05-04-22, 09:56 AM
P
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 28,578
Received 1,707 Upvotes on 1,525 Posts
One story I've heard is that "gauge" came about at the beginning of the industrial revolution. Wire was one of the first forms/shapes of steel. Ordering by weight was easy but how do you specify what diameter wire you want. So they term "gauge" came about from the number of times they drew/stretched the wire. The more stretches/gauges the smaller/thinner the wire became. Then later in they started flattening wire into sheets and the term gauge stuck. That's why larger numbers are thinner (opposite of what you'd expect). Why there isn't a direct formula or ratio between gauges. And why gauge thickness varies depending on the material. Makes you want to adopt the metric system doesn't it.
 
CircuitBreaker voted this post useful.
  #5  
Old 05-04-22, 06:51 AM
T
Member
Thread Starter
Join Date: Jan 2015
Location: USA
Posts: 915
Received 86 Upvotes on 76 Posts
Dane, I don't disagree as that's what I did. But I assume there should be a formula. I doubt if gauge is arbitrary.
 
  #6  
Old 05-04-22, 07:49 AM
Norm201's Avatar
Member
Join Date: Sep 2013
Location: United States
Posts: 11,568
Received 647 Upvotes on 572 Posts
Actually I think it is. A quick glance did not seem to show any mathematical ratio or type of relation between the thicknesses. However there is a formula that explains how a gauge is determined in terms of weight vs thickness as can be shown at this web site:
How to Calculate Steel Gauge to Inches (sciencing.com)

But I don't see any relation between thickness. But the numbers, though may be arbitrary, they are set in stone. In other words a 29 gauge sheet of metal is not determined by the thickness of the preceding gauge of 28.
I might be wrong!
 
  #7  
Old 05-05-22, 04:12 AM
T
Member
Thread Starter
Join Date: Jan 2015
Location: USA
Posts: 915
Received 86 Upvotes on 76 Posts
This turns out to be more interesting (to me) than I expected. Dane, based on your post I did some research on the history of gauge. I came across an article from the Association of Anaesthetists. It seemed like an unusual place but apparently gauge is used in needle specs.

Gauge goes back at least to 1200 in Germany. It seems gauge related to the draw of wire through a hole to narrow it. Each draw would narrow the wire, which is why gauge is higher for smaller diameters. While this article addresses gauge for wire, it doesn't fully address sheet metal which, I think has a different history related to weight.

For anyone interested in gauge as much as I was, here's the article.
https://associationofanaesthetists-p...4.1999.00895.x
 
  #8  
Old 05-05-22, 05:32 AM
Marq1's Avatar
Member
Join Date: Sep 2016
Location: USA MI
Posts: 9,954
Received 1,057 Upvotes on 959 Posts
​​​​​
Yes! Metric!
As I have stated before, English units are used by the thee super powers of the world, The United States of America, Myanmar, and Liberia.

What kills me, at work we make a lot of prototype parts to support the engineering organization. Everything is designed in metric and engineers are shocked when they cant get their parts fabricated to the material thickness as designed and have no idea that sheet metal is only available in standard gauge thicknesses.

​​​​​​​And these are degreed engineers!
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: