18 Gauge Galvanized Steel

18 gauge galvanized steel adheres to industry-standard specifications with a standard thickness of 1.31mm (equivalent to 0.0516 inches). It offers excellent corrosion resistance, structural strength, and workability, making it suitable for both large-scale structural support in major projects and smaller-scale applications.

Wanzhi Steel supplies premium 18-gauge galvanized steel products, offering good strength, excellent formability, and cost-effectiveness. We support slitting, cutting, and forming services, providing various product types (coils, flat sheets, corrugated sheets, strips) with flexible zinc coating options ranging from 30-275g/㎡.

18 gauge Galvanized Steel Specifications

Item	18 gauge Galvanized steel
Nominal Specifications	18 Gauge (AWG)
Thickness	1.31 mm (0.0516 inches)
Width	≤1300mm
Length	Coils or fixed-length sheets
Surface Treatment Process	Electro-galvanized and hot-dip galvanized
Zinc Layer Weight	Z30 – Z275g/㎡
Spangle Type	Zero spangles, Small spangles, Regular spangles, Big spangles
Product Type	Sheet/Coil/Strip
Substrate Material	DX51D/DX52D/S250GD/S350GD/S550GD/SPCC/SGCC/DC01/DC03
Standard	GB, EN, JIS, ASTM
Payment	TT 30% prepayment + 70% balance
Certifications	ISO 9001, ISO 14001, SGS, CE
MOQ	10 TONS
Packaging	Standard export packaging

18 Gauge Galvanized Steel Advantages

Exceptional Strength and Workability

With a substrate thickness of 1.31mm, this “medium-lightweight” steel offers both load-bearing capacity and excellent flexibility, meeting demands for cutting, bending, welding, stamping, and other advanced processing operations.

Reliable and Versatile Corrosion Protection

Utilizing hot-dip galvanizing or electrogalvanizing processes, the zinc coating exhibits strong adhesion and uniform distribution. Coating weights range from 30-275g/m², allowing flexible selection based on application scenarios: opt for lower zinc coatings in dry environments, and higher zinc coatings in coastal or humid conditions.

High Cost-Effectiveness

Compared to thicker steel plates with equivalent zinc coating grades, Grade 18 specifications effectively reduce material costs. With mature production processes and controllable mass production costs, it represents an exceptionally cost-effective corrosion-resistant steel solution.

What is 18 Gauge GI Steel Used For?

• Construction industry: It can be used to make building roofs and walls, and can also be used as support frames, beams, etc. to provide stable structural support.
• Agricultural field: After pressing the tiles, farm fences, livestock fences, etc. can be made. Its strength and corrosion resistance make it an ideal fence material. It is also often used as a structural component.
• Industrial manufacturing: Gauge 18 galvanized steel can be used to make parts such as shells and brackets. It is also often used to make storage tanks, containers, etc. for storing various liquids and gases.
• Transportation: It can be used to make car, truck, subway, train body parts, chassis, etc., and can also be used to make highway guardrails, signs, bus stops, etc.
• Home and decoration: It can make furniture frames and support parts, such as chairs, tables, etc., community carports, and slide structures.
• Decorative materials: The colors are simple and versatile, so it is also often used as decorative materials, such as wall decorative panels, ceilings, commercial exterior wall coverings, etc.

What is 18 gauge?

“Gauge” is an industry-standard designation for metal sheet thickness, originating from the relationship between steel processing cycles and thickness—more processing cycles result in thinner sheets. This established the core principle that gauge numbers are inversely proportional to thickness:

• Lower gauge numbers indicate thicker sheets; higher gauge numbers indicate thinner sheets.
• According to the galvanized steel industry’s standard conversion chart, 18 gauge corresponds to a standard thickness of 0.0516 inches or 1.310 mm.
• Note that gauge-to-thickness conversions vary slightly for different materials (e.g., stainless steel, aluminum), requiring careful differentiation.

GI Steel Gauge and Thickness Comparison Table

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

Gauge Number	Inches	MM
10	0.1382	3.51028
11	0.1233	3.13182
12	0.1084	2.75336
13	0.0934	2.37236
14	0.0785	1.9939
15	0.071	1.8034
16	0.0635	1.6129
17	0.0575	1.4605
18	0.0516	1.31064
19	0.0456	0.15824
20	0.0396	1.00584
21	0.0366	0.92964
22	0.0336	0.85344
23	0.0306	0.77724
24	0.0276	0.7004
25	0.0247	0.62738
26	0.0217	0.55118
27	0.0202	0.51308
28	0.0187	0.47498
29	0.0172	0.43688
30	0.0157	0.39878
31	0.0142	0.36068
32	0.0134	0.34036

FAQs

Q1: Which is thicker, 14-gauge or 18-gauge galvanized steel?

A: 14-gauge is thicker. According to gauge specifications, lower numbers indicate greater thickness. 14-gauge offers higher strength and is suitable for load-bearing applications; 18-gauge provides better workability and is ideal for general-purpose scenarios.

Q2: What zinc coating and surface treatment are recommended for ventilation ducts?

A: For indoor ducts, Z90 (G60) is sufficient. For humid or outdoor environments, Z120-Z275 (G90) is recommended. For surface treatment, choose fingerprint-resistant (N) coating. It prevents rust, provides excellent adhesion for subsequent painting (if needed), and facilitates processing.

Q3: Can 18-gauge galvanized steel be used for outdoor fencing?

A: Yes, but note: For low-height, low-stress decorative or simple fencing, 18-gauge is an economical choice. However, for impact-resistant safety fencing, upgrade to thicker 16- or 14-gauge steel with a Z180 (G90) or higher zinc coating.

key Points to Note Before Purchasing

1. Zinc layer standard: clarify the type of galvanizing (electrogalvanizing/hot-dip galvanizing) and the weight of the zinc layer (such as Z60/Z180/Z275).

2. Substrate parameters: material selection (Q195/Q235/SPCC, etc.), thickness tolerance (such as ±0.05mm) and tensile strength (≥300MPa)

3. Surface requirements: zero zinc flower/small zinc flower/conventional zinc flower, oiling, fingerprint resistance and other treatments.

4. Application adaptability: the outdoor environment requires a thickened zinc layer, deep processing requirements (bending/welding) need to be stated in advance, please contact us for recommendations.

5. Supplier qualifications: check the factory ISO certification, test report (SGS/MTC), and confirm the production capacity and delivery period.6. After-sales service: whether technical guidance is provided, such as cutting and installation suggestions.Wanzhi Steel Tips: Welcome to request free samples and test them before purchasing in bulk!

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.

Wanzhi Package

Galvanized Steel Manufacturer- Wanzhi Steel

Why Choose Wanzhi Steel as Your Supplier?

• Production Capabilities: Equipped with three galvanized steel production lines featuring advanced manufacturing processes, ensuring consistent zinc coating thickness and uniformity. With ample production capacity, we can handle large-volume orders.
• Rigorous Inspection Process: From raw material procurement and galvanizing to finished product shipment, products undergo multiple tests including zinc coating thickness measurement, adhesion testing, and salt spray corrosion testing.
• Extensive Experience: With over 14 years of production and export expertise, we are familiar with standards across different countries and can provide galvanized steel products meeting various global specifications.

Wanzhi Steel’s Value-Added Services

• Slitting Service: Wide coils can be slit into galvanized steel strips of any width you require (e.g., 200mm, 300mm), saving your procurement time.
• Cutting: Galvanized steel coils can be sheared to your desired lengths (e.g., 2m, 3m) to produce galvanized flat sheets.
• Pre-Punching: We process galvanized coils or sheets with pre-punched hole patterns according to your provided drawings.
• Forming: Using our diverse roll forming equipment, we shape corrugated/trapezoidal panels for direct use in roofing or wall applications.

As an industry-leading supplier of galvanized steel, Wanzhi Steel operates state-of-the-art hot-dip galvanizing production lines. Submit your requirements immediately (thickness, width, zinc coating, application), and you will receive a clear quotation with technical parameter recommendations within 10 hours, Contact us now!