1. Introduction to Mild Steel
Mild steel, also known as low-carbon steel, is one of the most widely used metals in the world. It is the backbone of modern industry — from construction and automotive manufacturing to machinery and household products. The reason is simple: mild steel offers a perfect balance between strength, ductility, and affordability.
At Huaxiao-Alloy, headquartered in Shanghai, China, with factories located in Wuxi, Foshan, and Baoshan, we specialize in supplying and exporting high-quality mild steel sheets, coils, and plates to global markets. With over a decade of export experience, we understand that one of the most important aspects for international buyers is knowing the exact thickness and gauge of the mild steel they purchase.
This guide provides a comprehensive Mild Steel Gauge Thickness Chart — complete with dual-unit conversion (inch ↔ mm), industry applications, and expert insights. Whether you’re a fabricator, distributor, or procurement officer, this article will help you choose the right material and gauge for your project.
2. What Is a Steel Gauge?
A gauge is a standard measurement that indicates the thickness of sheet metal. It originated in the wire-drawing industry but is now widely used for sheet and plate metals. The higher the gauge number, the thinner the steel sheet.
For instance:
10 gauge mild steel ≈ 0.1345 inch (3.42 mm)
20 gauge mild steel ≈ 0.0359 inch (0.91 mm)
Different standards exist for ferrous (iron-based) and non-ferrous metals. Mild steel follows the U.S. Standard Gauge (USSG), while stainless steel and aluminum use slightly different scales.
For international buyers, confusion often arises because metric thickness (mm) is more intuitive, but gauge sizes are still commonly used in the U.S., Canada, and some parts of Asia. This is why having both units in one chart is crucial.
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3. Mild Steel Gauge Thickness Chart (Imperial & Metric)
Below is the comprehensive mild steel gauge chart showing gauge numbers, thickness in inches and millimeters, and approximate weight per square meter.
| Gauge (G) | Thickness (inch) | Thickness (mm) | Weight (kg/m²) |
|---|---|---|---|
| 4 | 0.2242 | 5.70 | 44.7 |
| 5 | 0.2092 | 5.31 | 41.6 |
| 6 | 0.1943 | 4.94 | 38.2 |
| 7 | 0.1793 | 4.55 | 35.3 |
| 8 | 0.1644 | 4.18 | 32.2 |
| 9 | 0.1495 | 3.80 | 29.3 |
| 10 | 0.1345 | 3.42 | 26.4 |
| 11 | 0.1196 | 3.04 | 23.5 |
| 12 | 0.1046 | 2.66 | 20.5 |
| 13 | 0.0897 | 2.28 | 17.7 |
| 14 | 0.0747 | 1.90 | 14.7 |
| 15 | 0.0673 | 1.71 | 13.2 |
| 16 | 0.0598 | 1.52 | 11.7 |
| 17 | 0.0538 | 1.37 | 10.4 |
| 18 | 0.0478 | 1.21 | 9.2 |
| 19 | 0.0418 | 1.06 | 8.0 |
| 20 | 0.0359 | 0.91 | 6.9 |
| 21 | 0.0329 | 0.84 | 6.3 |
| 22 | 0.0299 | 0.76 | 5.7 |
| 23 | 0.0269 | 0.68 | 5.1 |
| 24 | 0.0239 | 0.61 | 4.5 |
| 25 | 0.0209 | 0.53 | 3.9 |
| 26 | 0.0179 | 0.46 | 3.3 |
| 27 | 0.0164 | 0.42 | 3.0 |
| 28 | 0.0149 | 0.38 | 2.7 |
| 29 | 0.0135 | 0.34 | 2.4 |
| 30 | 0.0120 | 0.30 | 2.1 |
Note: Values are based on U.S. Standard Gauge for mild steel. Slight variations may occur depending on manufacturing tolerance.
4. Understanding the Relationship Between Gauge and Strength
As gauge number increases, the sheet becomes thinner — but that doesn’t necessarily mean weaker. The strength of mild steel depends on:
Thickness (gauge)
Material composition (carbon content)
Heat treatment and rolling method
For example:
10 gauge (3.42 mm) sheet is ideal for heavy-duty applications such as truck bodies and equipment panels.
20 gauge (0.91 mm) sheet is commonly used for automotive interiors, ducting, and enclosures.
Huaxiao-Alloy provides both hot-rolled (HR) and cold-rolled (CR) mild steel, ensuring mechanical properties meet or exceed ASTM and EN standards.
5. Applications of Different Mild Steel Gauges
Each gauge level has specific industrial applications. Below is a simplified reference:
| Gauge | Thickness (mm) | Typical Application |
|---|---|---|
| 4–8 | 4.18–5.7 | Heavy machinery frames, bridges, shipbuilding |
| 9–12 | 2.6–3.8 | Structural beams, containers, storage tanks |
| 13–16 | 1.5–2.3 | Automotive panels, electrical cabinets |
| 17–20 | 0.9–1.3 | Appliances, ducting, metal furniture |
| 21–30 | 0.3–0.8 | Light fixtures, decorative panels, enclosures |
Huaxiao-Alloy’s engineers can also recommend the most suitable gauge based on your product design, bending radius, and forming process.
6. How to Choose the Right Mild Steel Gauge
Choosing the correct gauge depends on your application, load requirements, and manufacturing process. Consider the following:
Structural Strength:
For load-bearing parts, use 10–14 gauge materials.Weight Reduction:
For lightweight assemblies (like automotive interiors), select 18–22 gauge.Formability:
Thinner gauges are easier to bend and form but may need additional reinforcement.Cost Efficiency:
Thicker sheets cost more per square meter; finding the balance is key.
🔧 Pro Tip: If you are unsure which gauge fits your application, Huaxiao-Alloy’s technical team can recommend an optimal thickness after reviewing your drawings or CAD files.
7. Hot Rolled vs Cold Rolled Mild Steel
| Property | Hot Rolled Mild Steel | Cold Rolled Mild Steel |
|---|---|---|
| Surface Finish | Rough, scaled | Smooth, glossy |
| Dimensional Accuracy | Lower | Higher |
| Strength | Good | Better (due to strain hardening) |
| Cost | Lower | Slightly higher |
| Common Gauges | 4–12 | 13–30 |
Huaxiao-Alloy supplies both HR and CR mild steel in coils, sheets, and plates, supporting thicknesses from 0.3 mm to 50 mm. Our materials are sourced from certified Chinese mills and exported globally with full Mill Test Certificates (MTC).
8. Why Choose Huaxiao-Alloy as Your Mild Steel Supplier
When sourcing mild steel internationally, reliability and consistency are vital.
Here’s what makes Huaxiao-Alloy stand out:
🌍 Global Export Expertise: Decades of experience shipping to over 60 countries.
🏭 Strategic Factory Locations: Wuxi, Foshan, and Shanghai — the heart of China’s steel industry.
⚙️ Full Product Range: Coils, plates, pipes, bars, and custom-cut sheets.
📜 Certifications: ISO 9001, SGS, BV inspection supported.
🚢 Fast Delivery: Stable logistics and long-term partnerships with top freight carriers.
💬 Dedicated Service: English-speaking sales engineers ready to provide quick quotations.
👉 Contact Huaxiao-Alloy today for customized gauge thickness options and free consultation on your next steel procurement project.
📧 Email: [email protected] | 🌐 Website: www.huaxiao-alloy.com
A: 1 mm mild steel corresponds approximately to 20 gauge in the U.S. Standard Gauge system.
A: Typically, 4 gauge (5.7 mm) is the thickest commonly available in sheet form. Thicker options are classified as plates.
A: You can refer to the conversion chart above or contact Huaxiao-Alloy for digital tools and downloadable thickness conversion sheets.
A: Yes. Mild steel is a type of low-carbon steel containing less than 0.25% carbon, offering superior ductility and weldability.
A: Absolutely. Huaxiao-Alloy can supply non-standard thicknesses or cut-to-length sheets based on your specifications.
A: Hot rolled (black), cold rolled (bright), galvanized, and pre-painted finishes are all available.
A: Simply email [email protected] with your required gauge, dimensions, and quantity — our export team will respond within 24 hours.
10. Conclusion — Choose Precision, Choose Huaxiao-Alloy
Selecting the correct mild steel gauge is crucial for ensuring both performance and cost efficiency. With this complete chart and expert guidance from Huaxiao-Alloy, global buyers can make accurate, informed decisions with confidence.
As a trusted Chinese exporter, Huaxiao-Alloy provides:
Precise gauge measurement
Reliable quality control
Competitive global pricing
Fast, flexible shipment
📩 Ready to get a quote?
Contact us now at export@huaxiao-alloy.com or visit www.huaxiao-alloy.com.
Your trusted steel partner — Huaxiao-Alloy, powering the world with precision metal solutions.
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