Sheet Metal Gauge Chart: 18 Gauge Thickness in MM
When working with sheet metal, the term “gauge” refers to the material’s thickness or thickness range. However, persons unfamiliar with the gauge system may struggle to understand what a given gauge, such as 18 gauge steel, means. To clarify, this blog will explain the gauge system and provide a useful sheet metal gauge chart.
The gauge system is a standardized way for measuring and categorizing the thickness of sheet metal. It assigns numerical values to varying thicknesses, with larger gauge numbers indicating thinner sheets. For example, 18 gauge steel is thicker than 22 gauge steel. If you need precise measurements, the 18 gauge thickness in mm can help you establish the actual size of the material, and translating 18 gauge to mm gives you a clear reference for manufacture and design.
The blog will include a sheet metal gauge chart to help you visualize and comprehend the various gauges and accompanying thicknesses. This chart will show the gauge numbers and the associated thickness in inches or millimeters, making it easy to understand the measurements of various gauges.
Readers will have a better grasp of how to interpret and deal with sheet metal of varied thicknesses after being given an explanation of the gauge system and shown a sheet metal gauge chart. Knowing the 18 gauge thickness in millimeters is very useful for anyone working in industries like manufacturing, construction, or metal fabrication, where working with sheet metal is frequent.
How are Sheet Metal Gauges Used?
Gauges are used to define the thickness of sheet metal, however they are neither standardised or based on standard or metric measurements. The gauge values are independent and do not have a direct relationship to specific measurements. A gauge conversion chart is used to determine the exact thickness of sheet metal in inches or millimeters.
This chart shows the corresponding thickness values for each gauge. According to a gauge conversion chart, 18 gauge thickness in mm equals roughly 1.214 millimetres (0.0478 inches). Understanding 18 gauge to mm conversion aids in accurate measurements while working with various sheet metals. It is vital to note that the gauge number is unrelated to the actual measurements.
Different gauge systems are used for various metal kinds. For example, under one gauge system, 18 gauge steel is 0.0478 inches thick, whereas 18 gauge aluminum is 0.0403 inches thick. These variances underscore the significance of consulting to a gauge chart to confirm that the metal satisfies the specifications.
Using a gauge conversion chart, anyone may precisely determine the thickness of sheet metal, regardless of the gauge system or metal type utilized. This information is useful in a variety of industries, including manufacturing, building, and metal fabrication, where exact measurements are required for successful operations.
History of the Gauge System
The gauge system is a historic method for measuring metal thickness, with origins in the British wire industry. Originally, it was intended to define the diameter of drawn metal wires before standardized and metric measurement methods became widely used. Over time, this technique became extensively used for both wire and sheet metal, providing a convenient way to specify material thickness.
Although modern electrical cables are frequently measured by their cross-sectional area in square millimetres, the standard wire gauge (SWG) is still widely used for sheet metal. When working with sheet metal, thickness can be reliably measured with equipment such as callipers or ultrasonic gauges, which generally come with reference charts unique to the metal being utilized.
Sheet Metal Gauge Charts
| Mild Steel Gauge Chart | ||
| GaugeNumber | Inches | MM |
| 7 | .1793 | 4.554 |
| 8 | .1644 | 4.175 |
| 9 | .1495 | 3.797 |
| 10 | .1345 | 3.416 |
| 11 | .1196 | 3.038 |
| 12 | .1046 | 2.656 |
| 14 | .0747 | 1.897 |
| 16 | .0598 | 1.518 |
| 18 | .0478 | 1.214 |
| 20 | .0359 | .911 |
| 22 | .0299 | .759 |
| 24 | .0239 | .607 |
| 26 | .0179 | .454 |
| 28 | .0149 | .378 |
| Aluminum Gauge Chart* | ||
| GaugeNumber | Inches | MM |
| 7 | .1443 | 3.665 |
| 8 | .1285 | 3.264 |
| 9 | .1144 | 2.906 |
| 10 | .1019 | 2.588 |
| 11 | .09074 | 2.305 |
| 12 | .08081 | 2.053 |
| 14 | .06408 | 1.628 |
| 16 | .05082 | 1.291 |
| 18 | .04030 | 1.024 |
| 20 | .03196 | .812 |
| 22 | .02535 | .644 |
| 24 | .02010 | .511 |
| 26 | .01594 | .405 |
| 28 | .01264 | .321 |
| 30 | .01003 | .255 |
| Stainless Steel Gauge Chart* | ||
| GaugeNumber | Inches | MM |
| 8 | .17187 | 4.365 |
| 9 | .15625 | 3.968 |
| 10 | .14062 | 3.571 |
| 11 | .125 | 3.175 |
| 12 | .10937 | 2.778 |
| 14 | .07812 | 1.984 |
| 16 | .0625 | 1.587 |
| 18 | .050 | 1.270 |
| 20 | .0375 | .9525 |
| 22 | .03125 | .7937 |
| 24 | .025 | .635 |
| 26 | .01875 | .476 |
| 28 | .01562 | .396 |
| 30 | .0125 | .3175 |
| Galvanized Steel Gauge Chart* | ||
| GaugeNumber | Inches | MM |
| 8 | .1681 | 4.269 |
| 9 | .1532 | 3.891 |
| 10 | .1382 | 3.510 |
| 11 | .1233 | 3.1318 |
| 12 | .1084 | 2.753 |
| 14 | .0785 | 1.9939 |
| 16 | .0635 | 1.6129 |
| 18 | .0516 | 1.310 |
| 20 | .0396 | 1.005 |
| 22 | .0336 | .853 |
| 24 | .0276 | .701 |
| 26 | .0217 | .551 |
| 28 | .0187 | .474 |
| 30 | .0157 | .398 |
| Brass Gauge Chart* | ||
| GaugeNumber | Inches | MM |
| 7 | .1443 | 3.665 |
| 8 | .1285 | 3.264 |
| 9 | .1144 | 2.906 |
| 10 | .1019 | 2.588 |
| 11 | .09074 | 2.305 |
| 12 | .08081 | 2.053 |
| 14 | .06408 | 1.628 |
| 16 | .05082 | 1.291 |
| 18 | .04030 | 1.024 |
| 20 | .03196 | .812 |
| 22 | .02535 | .644 |
| 24 | .02010 | .511 |
| 26 | .01594 | .405 |
| 28 | .01264 | .321 |
| 30 | .01003 | .255 |
| Copper Gauge Chart* | ||
| GaugeNumber | Inches | MM |
| 7 | .180 | 4.572 |
| 8 | .165 | 4.191 |
| 9 | .148 | 3.759 |
| 10 | .134 | 3.404 |
| 11 | .120 | 3.048 |
| 12 | .109 | 2.769 |
| 14 | .083 | 2.108 |
| 16 | .065 | 1.651 |
| 18 | .049 | 1.245 |
| 20 | .035 | .889 |
| 22 | .028 | .711 |
| 24 | .022 | .559 |
| 26 | .018 | .457 |
| 28 | .014 | .356 |
| 30 | .012 | .305 |
GAUGE CHART
| GAUGE # | BRASS & ALUMINUM SHEETS | COLD & HOT ROLLED STEEL SHEETS | ALU., COPPER, BRASS,& STEEL TUBES COPPER SHEETS HOOP STEEL | STAINLESS STEEL SHEETS | GALVANIZED STEEL SHEETS | |||||
| INCHES | MM | INCHES | MM | INCHES | MM | INCHES | MM | INCHES | MM | |
| 7 | 1443 | 3.665 | 0.1793 | 4.554 | 0.180 | 4.572 | ||||
| 8 | 0.1285 | 3.264 | 0.1644 | 4.175 | 0.165 | 4.191 | 0.17187 | 4.365 | 0.1681 | 4.269 |
| 9 | 0.1144 | 2.906 | 0.1495 | 3.797 | 0.148 | 3.759 | 0.15625 | 3.968 | 0.1532 | 3.891 |
| 10 | 0.1019 | 2.588 | 0.1345 | 3.416 | 0.134 | 3.404 | 0.14062 | 3.571 | 0.1382 | 3.510 |
| 11 | 0.09074 | 2.305 | 0.1196 | 3.038 | 0.120 | 3.048 | 0.125 | 3.175 | 0.1233 | 3.1318 |
| 12 | 0.08081 | 2.053 | 0.1046 | 2.656 | 0.109 | 2.769 | 0.10937 | 2.778 | 0.1084 | 2.753 |
| 14 | 0.06408 | 1.628 | 0.0747 | 1.897 | 0.083 | 2.108 | 0.07812 | 1.984 | 0.0785 | 1.9939 |
| 16 | 0.05082 | 1.291 | 0.0598 | 1.518 | 0.065 | 1.651 | 0.0625 | 1.587 | 0.0635 | 1.6129 |
| 18 | 0.04030 | 1.024 | 0.0478 | 1.214 | 0.049 | 1.245 | 0.050 | 1.270 | 0.0516 | 1.310 |
| 20 | 0.03196 | 0.812 | 0.0359 | 0.911 | 0.035 | 0.889 | 0.0375 | 0.9525 | 0.0396 | 1.005 |
| 22 | 0.02535 | 0.644 | 0.0299 | 0.759 | 0.028 | 0.711 | 0.03125 | 0.7937 | 0.0336 | 0.853 |
| 24 | 0.02010 | 0.511 | 0.0239 | 0.607 | 0.022 | 0.559 | 0.025 | 0.635 | 0.0276 | 0.701 |
| 26 | 0.01594 | 0.405 | 0.0179 | 0.454 | 0.018 | 0.457 | 0.01875 | 0.476 | 0.0217 | 0.551 |
| 28 | 0.01264 | 0.321 | 0.0149 | 0.378 | 0.014 | 0.356 | 0.01562 | 0.396 | 0.0187 | 0.474 |
| 30 | 0.01003 | 0.255 | 0.0120 | 0.305 | 0.012 | 0.305 | 0.0125 | 0.3175 | 0.0157 | 0.398 |
Standard Steel Gauge Chart
| Gauge | Thickness (in) | Thickness (mm) | Weight (lb/ft²) | Weight (kg/m²) |
| 3 | 0.2391 | 6.073 | 9.754 | 47.624 |
| 4 | 0.2242 | 5.695 | 9.146 | 44.656 |
| 5 | 0.2092 | 5.314 | 8.534 | 41.668 |
| 6 | 0.1943 | 4.935 | 7.927 | 38.701 |
| 7 | 0.1793 | 4.554 | 7.315 | 35.713 |
| 8 | 0.1644 | 4.176 | 6.707 | 32.745 |
| 9 | 0.1495 | 3.797 | 6.099 | 29.777 |
| 10 | 0.1345 | 3.416 | 5.487 | 26.790 |
| 11 | 0.1196 | 3.038 | 4.879 | 23.822 |
| 12 | 0.1046 | 2.657 | 4.267 | 20.834 |
| 13 | 0.0897 | 2.278 | 3.659 | 17.866 |
| 14 | 0.0747 | 1.897 | 3.047 | 14.879 |
| 15 | 0.0673 | 1.709 | 2.746 | 13.405 |
| 16 | 0.0598 | 1.519 | 2.440 | 11.911 |
| 17 | 0.0538 | 1.367 | 2.195 | 10.716 |
| 18 | 0.0478 | 1.214 | 1.950 | 9.521 |
| 19 | 0.0418 | 1.062 | 1.705 | 8.326 |
| 20 | 0.0359 | 0.912 | 1.465 | 7.151 |
| 21 | 0.0329 | 0.836 | 1.342 | 6.553 |
| 22 | 0.0299 | 0.759 | 1.220 | 5.955 |
| 23 | 0.0269 | 0.683 | 1.097 | 5.358 |
| 24 | 0.0239 | 0.607 | 0.975 | 4.760 |
| 25 | 0.0209 | 0.531 | 0.853 | 4.163 |
| 26 | 0.0179 | 0.455 | 0.730 | 3.565 |
| 27 | 0.0164 | 0.417 | 0.669 | 3.267 |
| 28 | 0.0149 | 0.378 | 0.608 | 2.968 |
| 29 | 0.0135 | 0.343 | 0.551 | 2.689 |
| 30 | 0.0120 | 0.305 | 0.490 | 2.390 |
| 31 | 0.0105 | 0.267 | 0.428 | 2.091 |
| 32 | 0.0097 | 0.246 | 0.396 | 1.932 |
| 33 | 0.0090 | 0.229 | 0.367 | 1.793 |
| 34 | 0.0082 | 0.208 | 0.335 | 1.633 |
| 35 | 0.0075 | 0.191 | 0.306 | 1.494 |
| 36 | 0.0067 | 0.170 | 0.273 | 1.335 |
| 37 | 0.0064 | 0.163 | 0.261 | 1.275 |
| 38 | 0.0060 | 0.152 | 0.245 | 1.195 |
Zinc Gauge Chart
| Gauge | Thickness (in) | Thickness (mm) | Weight (lb/ft²) | Weight (kg/m²) |
| 28 | 1.0000 | 25.400 | 37.152 | 181.392 |
| 27 | 0.5000 | 12.700 | 18.576 | 90.696 |
| 26 | 0.3750 | 9.525 | 13.932 | 68.022 |
| 25 | 0.2500 | 6.350 | 9.288 | 45.348 |
| 24 | 0.1250 | 3.175 | 4.644 | 22.674 |
| 23 | 0.1000 | 2.540 | 3.715 | 18.139 |
| 22 | 0.0900 | 2.286 | 3.344 | 16.325 |
| 21 | 0.0800 | 2.032 | 2.972 | 14.511 |
| 20 | 0.0700 | 1.778 | 2.601 | 12.697 |
| 19 | 0.0600 | 1.524 | 2.229 | 10.884 |
| 18 | 0.0550 | 1.397 | 2.043 | 9.977 |
| 17 | 0.0500 | 1.270 | 1.858 | 9.070 |
| 16 | 0.0450 | 1.143 | 1.672 | 8.163 |
| 15 | 0.0400 | 1.016 | 1.486 | 7.256 |
| 14 | 0.0360 | 0.914 | 1.337 | 6.530 |
| 13 | 0.0320 | 0.813 | 1.189 | 5.805 |
| 12 | 0.0280 | 0.711 | 1.040 | 5.079 |
| 11 | 0.0240 | 0.610 | 0.892 | 4.353 |
| 10 | 0.0200 | 0.508 | 0.743 | 3.628 |
| 9 | 0.0180 | 0.457 | 0.669 | 3.265 |
| 8 | 0.0160 | 0.406 | 0.594 | 2.902 |
| 7 | 0.0140 | 0.356 | 0.520 | 2.539 |
| 6 | 0.0120 | 0.305 | 0.446 | 2.177 |
| 5 | 0.0100 | 0.254 | 0.372 | 1.814 |
| 4 | 0.0080 | 0.203 | 0.297 | 1.451 |
| 3 | 0.0060 | 0.152 | 0.223 | 1.088 |
| 2 | 0.0040 | 0.102 | 0.149 | 0.726 |
| 1 | 0.0020 | 0.051 | 0.074 | 0.363 |
Birmingham Gage (BG) Chart
| Gauge | Thickness (in) | Thickness (mm) |
| 0000000 | 0.6666 | 16.932 |
| 000000 | 0.6250 | 15.875 |
| 00000 | 0.5883 | 14.943 |
| 0000 | 0.5416 | 13.757 |
| 000 | 0.5000 | 12.700 |
| 00 | 0.4452 | 11.308 |
| 0 | 0.3964 | 10.069 |
| 1 | 0.3532 | 8.971 |
| 2 | 0.3147 | 7.993 |
| 3 | 0.2804 | 7.122 |
| 4 | 0.2500 | 6.350 |
| 5 | 0.2225 | 5.652 |
| 6 | 0.1981 | 5.032 |
| 7 | 0.1764 | 4.481 |
| 8 | 0.1570 | 3.988 |
| 9 | 0.1398 | 3.551 |
| 10 | 0.1250 | 3.175 |
| 11 | 0.1113 | 2.827 |
| 12 | 0.0991 | 2.517 |
| 13 | 0.0882 | 2.240 |
| 14 | 0.0785 | 1.994 |
| 15 | 0.0699 | 1.775 |
| 16 | 0.0625 | 1.588 |
| 17 | 0.0556 | 1.412 |
| 18 | 0.0495 | 1.257 |
| 19 | 0.0440 | 1.118 |
| 20 | 0.0392 | 0.996 |
| 21 | 0.0349 | 0.886 |
| 22 | 0.0312 | 0.792 |
| 23 | 0.0278 | 0.706 |
| 24 | 0.0247 | 0.627 |
| 25 | 0.0220 | 0.559 |
| 26 | 0.0196 | 0.498 |
| 27 | 0.0174 | 0.442 |
| 28 | 0.0156 | 0.396 |
| 29 | 0.0139 | 0.353 |
| 30 | 0.0123 | 0.312 |
| 31 | 0.0110 | 0.279 |
| 32 | 0.0098 | 0.249 |
| 33 | 0.0087 | 0.221 |
| 34 | 0.0077 | 0.196 |
| 35 | 0.0069 | 0.175 |
| 36 | 0.0061 | 0.155 |
| 37 | 0.0054 | 0.137 |
| 38 | 0.0048 | 0.122 |
| 39 | 0.0043 | 0.109 |
| 40 | 0.0038 | 0.097 |
| 41 | 0.0034 | 0.086 |
| 42 | 0.0030 | 0.076 |
| 43 | 0.0027 | 0.069 |
| 44 | 0.0024 | 0.061 |
| 45 | 0.0021 | 0.053 |
| 46 | 0.0019 | 0.048 |
| 47 | 0.0017 | 0.043 |
| 48 | 0.0016 | 0.041 |
| 49 | 0.0013 | 0.033 |
| 50 | 0.0012 | 0.030 |
| 51 | 0.0011 | 0.027 |
| 52 | 0.0010 | 0.024 |
Common Types of Sheet Metal to Consider
Choosing the right sheet metal type is the first step toward determining the correct gauge and ensuring project success. The following are some of the most prevalent sheet metals used in industry, architecture, and manufactured goods:
Zinc-plated steel: Zinc-coated steel provides corrosion prevention. Ideal for outdoor and/or damp settings (agricultural, solar mounting, automotive components, construction frames).
Stainless Steel: Stainless steel is made with at least 10.5% chromium to resist corrosion. Ideal for hygienic applications, medical equipment, architectural designs, and food-grade applications.
Aluminum: A lightweight and corrosion-resistant metal. It is widely utilized in aerospace, automotive, facades, food packaging, and other manufactured items.
Brass: A copper-zinc alloy recognized for its beautiful look and acoustic qualities. It is widely utilized in musical instruments, construction, plumbing, and electrical hookups.
Copper: A malleable metal with excellent conducting qualities. Common applications include electrical systems, plumbing, roofing and siding, industrial gear, and electronics.
Conclusion
Finally, the gauge method has been used in the metal manufacturing business for many years. It came from the British wire industry and was originally used to define the diameter of metal wires being drawn. It gradually expanded to include the thickness of sheet metal.
The gauge system is still widely used today, despite the advent of standard and metric measurement systems. It provides a simple and widely acknowledged technique of determining sheet metal thickness, enabling for effective industry communication.
Although gauge values are unaffected by standard or metric measurements, conversion charts are available to calculate the actual thickness in inches or millimeters. This ensures accuracy and consistency when working with sheet metal of different gauges.
Overall, the gauge system’s historical significance, universal acceptability, and practicality have helped to ensure its continued use in metal manufacture. It is an invaluable tool for experts in industries such as manufacturing, construction, and metal fabrication, allowing for better communication and precise measurements to ensure project success.
Newzel Industries
Newzel Industries stocks and supplies a diverse range of carbon steel, stainless steel, alloy steel, nickel alloy steel, and special metals. Our inventory includes a variety of shapes and forms, including sheets, plates, tubes, pipes, bars, and fittings, all designed to fulfill a wide range of industrial uses.
