SHEET METAL GAUGE CHART

SHEET METAL GAUGES

Sheet metal thickness is denoted by gauge, sometimes spelled gage, which indicates a standard thickness before processing.

Processing may include polishing, or the applying of protective plastics which will decrease or increase a sheet's thickness respectively.

As the gauge number increases the material's thickness decreases.

Gauge #Standard Steel
(Inches)
Standard Steel
(mm)
Strip / Tubing
(Inches)
Non-Ferrous /
Aluminum
(Inches)
Non-Ferrous /
Aluminum
(mm)
Galvanized
Steel
(Inches)
Galvanized
Steel
(mm)
US Standard
0000000-------0.5000
000000-- -0.580014.732--0.4688
00000--0.5000.516513.119--0.4375
0000-- 0.4540.460011.684--0.4063
000--0.4250.409610.404--0.3750
00-- 0.3800.36489.266--0.3438
0--0.3400.32498.252--0.3125
1-- 0.3000.28937.348--0.2813
2--0.2840.25766.543--0.2656
30.23916.073 0.2590.22945.827--0.2500
40.22425.6950.2380.20435.189--0.2344
50.2092 5.3140.2200.18194.620--0.2188
60.19434.9350.2030.16204.115--0.2031
7 0.17934.5540.1800.14433.665--0.1875
80.16444.1760.1650.12853.264-4.2700.1719
90.14953.7970.1480.11442.9060.15323.8910.1563
100.13453.4160.1340.10192.588 0.13823.5100.1406
110.11963.0380.1200.09072.3040.12333.1320.1250
120.10462.6570.109 0.08082.0520.10842.7530.1094
130.08972.2780.0950.07201.8290.09342.3720.0938
140.0747 1.8970.0830.06411.6280.07851.9940.0781
150.06731.7090.0720.05711.4500.07101.8030.0703
160.05981.5190.0650.05081.2900.06351.6130.0625
170.05381.3670.0580.04531.151 0.05751.4610.0563
180.04781.2140.0490.04031.0240.05161.3110.0500
190.04181.0620.042 0.03590.9120.04561.1580.0438
200.03590.9120.0350.03200.8130.03961.0060.0375
210.0329 0.8360.0320.02850.7240.03660.9300.0344
220.02990.7590.0280.02530.6430.03060.8530.0313
230.02690.6830.0250.02260.5740.02760.7770.0281
240.02390.6070.0220.02010.511 0.02470.7010.0250
250.02090.5310.0200.01790.4550.02170.6270.0219
260.01790.4550.018 0.01590.4040.02020.5510.0188
270.01640.417-0.01420.3610.01870.5130.0172
280.0149 0.378-0.01260.3200.01720.4750.0156
290.01350.343-0.01130.2870.01570.4370.0141
300.01200.305-0.01000.2540.01420.3990.0125
310.01050.267-0.00890.2260.01340.361 0.0109
320.00970.246-0.00800.203-0.3400.0102
330.00900.229-0.00710.180 --0.0094
340.00820.208-0.00630.160--0.0086
350.00750.191-0.00560.140 --0.0078
360.00670.170-0.00500.127--0.0070
37-0.163-0.0045 0.114--0.0066
38-0.152-0.0040.102--0.0063
39----0.089 --0.0059
40----0.079--0.0055
41------- 0.0053
42-------0.0051
43-------0.0049
44 -------0.0040

SHEET METAL THICKNESS TOLERANCES

Because sheets aremanufactured by rolling to the desired thickness there can be some crowning of the rollers, resulting in a thinner sheet on the edges compared to the center, this is shown in the table below.

STEEL / STAINLESS STEEL ALUMINIUM
THICKNESS36'' WIDE SHEET48'' WIDE SHEET THICKNESS 36'' WIDE SHEET48'' WIDE SHEET
0.170 -0.0300.00150.002 0.018 - 0.0280.0020.0025
0.031 - 0.0410.0020.003  0.029 - 0.0360.0020.0025
0.042 - 0.0590.0030.004 0.037 - 0.0450.00250.003
0.060 - 0.0730.0030.0045  0.046 - 0.0680.0030.004
0.074 - 0.0840.0040.0055 0.069 - 0.0760.0030.004
0.085 - 0.0990.004 0.006 0.077 - 0.0960.00350.004
0.100 - 0.1150.0050.007 0.097 - 0.1080.0040.005
0.116 - 0.131 0.0050.0075 0.109 - 0.1250.00450.005
0.132 - 0.1460.0060.009 0.126 - 0.1400.00450.005
0.147 - 0.1870.0070.0105 0.141 - 0.1720.0060.008
 0.173 - 0.2030.0070.010
 0.204 - 0.2490.0090.011

GALVANISED COATING THICKNESSES

As you can see from our first chart the galvanized columns are thicker than the regular steel.

After galvanizing, the continuous zinc coating is physically wiped using air knives to produce a uniform coating across the width of the strip.
The uniform coating consists almost entirely of unalloyed zinc and has sufficient ductility to withstand deep drawing or bending without damage.
A variety of coating weights and types are available, ranging up to just over 3 mils (76 µm) per side.
One of the most common zinc coatings is Class G90, which has 0.9 oz/ft² of sheet (total both sides) or about 0.80 mils (20 µm) thickness per side.
Continuous sheet galvanized coatings often get confused with batch hot-dip galvanized coatings because the term galvanizing is used interchangeably.
The tables below compare the available coating grades of continuous and batch hot-dip galvanizing and their
corresponding coating thicknesses.

CONTINIOUS SHEET GALVANISING

The number following the "G" coating grade designation correlates to the total thickness of zinc applied to both sides of the steel sheet.

DESIGNATIONBOTH SIDESONE SIDE
COATING GRADEoz/ft²oz/ft²mmum
G3603.601.803.2482.3
G3003.001.502.70 68.6
G2352.351.182.1253.7
G2102.101.051.8948.0
G1851.850.931.6742.3
G1651.650.831.4937.7
G1401.400.701.2632.0
G1151.150.581.0426.3
G90 0.900.450.8120.6
G60 / A600.600.300.5413.7
G40 / A400.400.200.369.1
G30 / A30 0.300.150.276.9
G01NO MINIMUM---

HOT DIP GALVANISING

Hot-dip Galvanizing: Coating grades are determined by the steel thickness and type.
Coating grades correspond to minimum zinc coating thickness on one side.

It is important to remember these are minimum coating thicknesses the galvanizer must achieve;
however, thicker coatings are common, assuring conformance to.

ONE SIDE
COATING GRADEoz/ft²mmum
1002.193.94100
851.863.3585
8017.53.15 80
751.642.9575
651.422.5665
601.312.3660
551.202.1755
501.101.9750
450.981.7745
350.771.3835