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18 gauge galvanized steel

Galvanized steel is widely used in applications where corrosion resistance is needed without the cost of stainless steel, and is considered superior in terms of cost and life-cycle. It can be identified by the crystallization patterning on the surface (often called a “spangle”). Today we’re taking an in-depth look at 18-gauge galvanized steel.

18 gauge galvanized steel wire

regular spangle GI coil

18 gauge Galvanized steel specifications

Technical Standard EN10147, EN10142, DIN 17162, JIS G3302, ASTM A653
Steel Grade Dx51D,  S280GD, S350GD, SGHC, SGH340, SGC340,SQ CR22 (230), FS, DDS, EDDS; or Customer’s Requirement
Thickness Customer’s Requirement
Width According To Customer’s Requirement
Type of Coating Hot Dipped Galvanized Steel(HDGI)
Zinc Coating 30-275g/m2
Surface Treatment Passivation(C), Oiling(O), Lacquer sealing(L), Phosphating(P), Untreated(U)
Surface Structure Regular spangle, Big spangle, Small spangle, Spangle-free
Quality Approved by SGS,ISO
ID 508mm/610mm
Coil Weight 3-8 TONS, Can be customized
Package Waterproof paper is inner packing, galvanized steel or coated steel sheet is outer packing, side guard plate, then wrapped by seven steel belts, or according to the customer’s requirement
Average Lead Time 5-20 days(Determined by order quantity)

What is 18 gauge?

The term “gauge” in steel refers to numbers that indicate the thickness of a piece of sheet metal, a measure that is vital in determining its strength and durability. The concept of steel gauge has been around for centuries, originating from the number of times steel had to be processed to reach a certain thickness.

Interestingly, the metal gauge number is inversely proportional to the steel’s thickness – the lower the gauge number, the thicker the steel, the higher the gauge number, the thinner the steel plate. This metric might seem a bit counter-intuitive, but it’s a standard that has been used in the industry for many years.

GI steel gauge thickness

18 gauge Galvanized steel features

  • Corrosion resistanceThe top layer of zinc reacts with oxygen to produce zinc oxide, which prevents further corrosion of the steel surface.
  • Long service lifeExcellent anti-corrosion properties.
  • AestheticsThe surface has a metallic luster, beautiful appearance
  • Processing performanceSmooth surface, no cracks, knots, thorns, rust and other defects, can be cut, bent, welded
  • Toughness and elasticityExcellent toughness and elasticity, can withstand a certain degree of tension and compression, not easy to break and deformation.
  • High strengthAble to withstand large loads.
  • Low production costEasy production process, low cost, so the price of galvanized steel is relatively low.

18 gauge GI angle steel

Zinc layer thickness

How thick is 18 gauge galvanized steel?

A gauge conversion chart can be used to determine the actual thickness of sheet metal in inches or millimeters.

These dimensions vary slightly between different materials such as stainless steel and aluminum – but should be

accurate enough for most everyday purposes.

                                                                        Galvanized steel gauge chart*
Gauge Number 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

For example, 18 gauge steel, according to the gauge conversion chart, is 0.0516 inch or 1.310 millimeter.

Is 14 or 18 gauge galvanized steel thicker

The rating for steel gauge may seem backward: the smaller the number, the thicker the steel.

18 gauge galvanized steel weight in kg

Gauge, also spelled ‘gage’, impacts the weight directly. A lower number implies a thicker sheet and higher weight and acquisition costs. An 18 gauge steel sheet weighs about 9.521 kg/m².

Sheet metal specification&weight

It comes to approximately 9.69 kg/m² for sheet steel. Interestingly, an 18 gauge aluminum coil is much lighter at 2.76 kg/m². It can make a budget-friendly selection in applications like construction, automotive, etc.

Is 18 gauge galvanized steel suitable for DIY projects?

The thickness of this material is perfect for DIY projects that will not undergo heavy handling or exposure to corrosive agents. It is a regular choice for decorative molding, paneling, trims, etc.

18 gauge corrugated GI steel

18 gauge GI steel sheet

An 18-gauge galvanized steel sheet is an excellent pick for home projects, crafts, hobby projects, etc.

What is 18 gauge steel used for?

  • Construction field -Roofing, wall panels, guardrails, steel ladders, fire doors and other aspects.
  • Home appliance field – shells and structural parts of household appliances such as refrigerators, washing machines, microwave ovens, etc.
  • Transportation – Ships, bridges, pipelines, transmission towers, solar energy racks.
  • Transportation equipment field -Aspects of transportation equipment such as shelves, forklifts, and loading trucks.
  • Power equipment – equipment such as transmission towers, utility poles, and belt trays.
  • Automotive industry – components such as body frames, doors, chassis and frames.


18 gauge GI steel applications

18 gauge GI steel container


Bridge structure

How strong is galvanized steel?

It has a standard yield strength of 470 to 550 MPa and a standard tensile strength of 510 to 600 MPa. Generally, this steel is roll-formed into products such as purlins, girts, and light structural profiles.

Tolerance range for GI steel

What diameter is 18 gauge?

Standard Wire Gauge ( SWG ) system ( also known as British or Imperial Wire Gauge).

American Wire Gauge ( AWG ) system of labeling ( also known as the Brown & Sharpe Wire Gauge).

The difference between SWG and AWG is most noticeable at thicker gauges (16 and thicker).

10 Gauge Wire 0.1280 in 3.251 mm 0.1019 in 2.588 mm Very thick wire. Often used by silver smiths using forging or welding techniques. Good for chokers, stiff bracelets, and rings.
12 Gauge Wire 0.1040 in 2.642 mm 0.0808 in 2.052 mm Still very thick wire, still hard to bend intricately by hand. Good for chokers, stiff bracelets, and even wire-sculpted rings.
14 Gauge Wire 0.0800 in 2.032 mm 0.0640 in 1.626 mm Heavier Wire. Good for chokers, stiff bracelets, and even wire-sculpted rings.
16 Gauge Wire 0.0640 in 1.626 mm 0.0508 in 1.290 mm Heavy Wire. Commonly used for chokers, heavy-duty clasps
18 Gauge Wire 0.0480 in 1.219 mm 0.0403 in 1.024 mm Med-Heavy Wire. Good for making clasps, chokers, and wire sculptures.

What is the difference between 18 gauge GI Steel and 304 steel?

18 gauge GI Steel contains 18% chromium and 8% nickel, while 304 contains 18% chromium and 8% nickel with 2-3% molybdenum.

                                                                                  GAUGE CHART
7 1443 3.665 .1793 4.554 .180 4.572
8 .1285 3.264 .1644 4.175 .165 4.191 .17817 4.365 .1681 4.269
9 .1144 2.906 .1495 3.797 .148 3.759 .15625 3.968 .1532 3.891
10 .1019 2.588 .1345 3.416 .134 3.404 .14062 3.571 .1382 3.510
11 .09074 2.305 .1196 3.038 .120 3.048 .125 3.175 .1233 3.1318
12 .08081 2.053 .1046 2.656 .109 2.769 .10937 2.778 .1084 2.753
14 .06408 1.628 .0747 1.897 .083 2.108 .07812 1.984 .0785 1.9939
16 .05082 1.291 .0598 1.518 .065 1.651 .0625 1.587 .0635 1.6129
18 .04030 1.024 .0478 1.214 .049 1.245 .050 1.270 .0516 1.310
20 .03196 .812 .0359 .911 .035 .889 .0375 .9525 .0396 1.005
22 .02535 .644 .0299 .759 .028 .711 .03125 .7937 .0336 .853
24 .02010 .511 .0239 .607 .022 .559 .025 .635 .0276 .701
26 .01594 .405 .0179 .454 .018 .457 .01875 .476 .0217 .551
28 .01264 .321 .0149 .378 .014 .356 .01562 .396 .0187 .474
30 .01003 .255 .0120 .305 .012 .305 .0125 .3175 .0157 .398

The additional molybdenum content in 304 gives it an enhanced resistance to corrosion caused by chlorides, making it ideal for use in marine environments, food processing, and chemical processing applications.

Is 18 gauge galvanized steel easy to bend?

It is easy to bend, but there are process requirements, and ASTM A 143 recommends that the minimum bending radius of any part hot-dipped galvanized after bending be at least three times the thickness of the material.

Cold working on bends

Cold working bending

This allows for some cold working in the bending area, thus avoiding cracking of the steel.

However, if cracking of the coating occurs, which is normal for 18 gauge galvanized steel, the cathodic properties of the galvanized coating will still protect the part after bending and cracking or crazing can be repaired using the methods in ASTM A780 to make the coating whole again.

How long will 18 gauge galvanized steel last?

With proper use and timely maintenance, if it is hot-dipped galvanized steel, in a dry environment, usually it has a service life of 70 years, different environments, different galvanizing processes, and different zinc layer thicknesses are the main factors in determining the specific use time of 16 gauge galvanized steel.

Service life in different environments

Will 18 gauge galvanized steel rust?

Yes, also no, it takes a very long time to rust, far better than other building materials, usually 50 years or more, so that means it hardly ever rusts, except in highly corrosive environments, where rusting is accelerated, so it will eventually rust. Other times it is still more durable, which is why everyone chooses it.   ——-  Reference for detailsDoes galvanized mental rust? 》

18 gauge galvanized steel

Use in humid environments

Where to buy 18 gauge galvanized steel for sale (with tips)?

Most investors would like to buy from galvanized steel factories in China because of the lower price. Just remember to find a reliable supplier. Before purchasing, please confirm some details, including specifications (thickness, width, length), zinc coating thickness, corrugations, quantity, etc. The MOQ of Wanzhi Steel is 5 tons. Welcome to talk with us for more details.

Final words

The above is an in-depth explanation of No. 18 galvanized steel. Its smooth and bright surface, high tensile strength, and corrosion resistance have many advantages that make various industries fall in love with it when selecting materials. Not only is the price lower than stainless steel, but on the basis of maintaining the characteristics of steel itself, The zinc on its surface also increases corrosion resistance, which is why it has been at the forefront of the steel family for many years.

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