Converting Sheet Metal Measurements to Gauge

 

Working with sheet metal is difficult and meticulous work. The job, the metal type, and the thickness all work together to determine what processes and tools you will use to complete your job. Making the wrong decision during this process can be not only frustrating but costly.  One of the most difficult parts of this process is working with the interchangeable terms “gauge” and millimeters or inches. Communication between customers, project managers, and technicians is critical for these jobs and an understanding of how to convert measurements in inches or millimeters to a certain gauge can save time, money, and added headache for your jobs.

 

The gauge systems has roots in the metal fabrication industry and was started in the wire industry, to describe the diameter of the metal wire so that wire drawers could quote metal based on the number of draws they had to perform to achieve a certain diameter. Since then, it has become the primary way of describing the thickness of both wire and sheet metal. It is important to remember the the gauge system is totally separate from completely separate from the metric and imperial measurement systems.

 

There are slightly different gauge measurements for different types of metal, too, since gauge is derived from weight. Because there are different measurements depending on the type of sheet metal being used, a conversion chart should be consulted to ensure that the tools and processes being used fit the parameters for the job.  A quick way to find the gauge equivalent to a measurement in inches or millimeters is by using a conversion chart like the one that can be found below. An even easier way to measure the gauge of your materials is by using a material thickness gauge by Miller, which can be placed on your keyring and can be purchased here.

 

Gauge (ga)

Standard Steel Thickness (inches)

Galvanized Steel Thickness (inches)

Aluminum Thickness (inches)

3

0.2391

-

0.2294

4

0.2242

 -

0.2043

5

0.2092

 -

0.1819

6

0.1943

 -

0.162

7

0.1793

 -

0.1443

8

0.1644

 -

0.1285

9

0.1495

0.1532

0.1144

10

0.1345

0.1382

0.1019

11

0.1196

0.1233

0.0907

12

0.1046

0.1084

0.0808

13

0.0897

0.0934

0.072

14

0.0747

0.0785

0.0641

15

0.0673

0.071

0.0571

16

0.0598

0.0635

0.0508

17

0.0538

0.0575

0.0453

18

0.0478

0.0516

0.0403

19

0.0418

0.0456

0.0359

20

0.0359

0.0396

0.032

21

0.0329

0.0366

0.0285

22

0.0299

0.0336

0.0253

23

0.0269

0.0306

0.0226

24

0.0239

0.0276

0.0201

25

0.0209

0.0247

0.0179

26

0.0179

0.0217

0.0159

27

0.0164

0.0202

0.0142

28

0.0149

0.0187

0.0126

29

0.0135

0.0172

0.0113

30

0.012

0.0157

0.01

31

0.0105

0.0142

0.0089

32

0.0097

0.0134

0.008

33

0.009

 -

0.0071

34

0.0082

 -

0.0063

35

0.0075

 -

0.0056

36

0.0067

 -

 

Enjoy content like this? At Welding Outfitter we care about you and your work! Shop Welding Outfitter for all your welding and industrial supply needs, there is always free shipping on orders $100 or more in the lower 48 states. Made it through the entire article? You must be really interested in converting measurements! As a gift to you we'd like to offer you a FREE Miller Material Thickness Gauge with a $25 purchase by using code MILLERGAUGE at checkout, and don't forget to sign up for our rewards program to earn points on all your future purchases!

Caleb Troe