Mild Steel Sheet Metal

Gauge Thickness (inches) Thickness (mm) Weight (lb/ft²)
7 0.179 4.554 2.26
8 0.164 4.175 2.09
9 0.150 3.797 1.93
10 0.135 3.416 1.76
11 0.120 3.038 1.59
12 0.105 2.656 1.43
14 0.075 1.897 1.02
16 0.060 1.518 0.81
18 0.048 1.214 0.63
20 0.036 0.911 0.46
22 0.030 0.759 0.37
24 0.024 0.607 0.29
26 0.018 0.454 0.21
28 0.015 0.378 0.17

Mild steel is easy to weld and shape, making it ideal for custom repairs. It’s also affordable and widely available.

However, mild steel lacks corrosion resistance, so it’s prone to rust if not treated.

Galvanized Steel Sheet Metal

Gauge Thickness (inches) Thickness (mm) Weight (lb/ft²)
8 0.168 4.269 2.12
9 0.153 3.891 1.96
10 0.138 3.510 1.79
11 0.123 3.132 1.62
12 0.108 2.753 1.45
14 0.079 1.994 1.04
16 0.064 1.613 0.82
18 0.052 1.310 0.66
20 0.040 1.005 0.49
22 0.034 0.853 0.38
24 0.028 0.701 0.30
26 0.022 0.551 0.23
28 0.019 0.474 0.18
30 0.016 0.398 0.14

Galvanized steel offers excellent corrosion resistance due to its zinc coating, which is useful for parts exposed to moisture.

Galvanized metal is more durable than other options, but can be difficult to weld and be slightly more expensive.

Stainless Steel Sheet Metal

Gauge Thickness (inches) Thickness (mm) Weight (lb/ft²)
8 0.172 4.365 2.39
9 0.156 3.968 2.15
10 0.141 3.571 1.93
11 0.125 3.175 1.70
12 0.109 2.778 1.50
14 0.078 1.984 1.05
16 0.062 1.587 0.81
18 0.050 1.270 0.63
20 0.038 0.953 0.48
22 0.031 0.794 0.38
24 0.025 0.635 0.30
26 0.019 0.476 0.23
28 0.016 0.397 0.18
30 0.013 0.318 0.14

Stainless steel provides superior corrosion resistance and strength, making it ideal for harsh conditions and high-wear areas.

Stainless steel has a higher cost than other metal options and challenging workability might be a drawback for some projects.

Aluminum

For vehicle repairs, mild steel is often used for ease of work, while galvanized steel is chosen for rust-prone areas. Stainless steel is reserved for high-performance or high-exposure components where its superior properties justify the higher cost.

Aluminum is lightweight and corrosion-resistant, making it ideal for body panels and trim. It’s easy to work with but can be expensive and less strong compared to other metals, which limits its use in structural repairs.

High-Strength Steel

High-strength steel provides increased durability and strength, making it suitable for structural components. It’s more expensive and harder to handle than mild steel, requiring precise work.

Composite Materials

Composites like carbon fiber are lightweight and strong, ideal for high-performance vehicles. They are costly and complex to repair but offer excellent strength-to-weight ratios.

Copper

Copper is great for thermal and electrical conductivity, used in radiators and wiring. It’s resistant to corrosion but is soft, expensive, and less suited for structural repairs.

These last four sheet metal options are not widely used if you're fixing up that old car or truck. They are good to know about, but often not your best choice.

Best Metal Type for Automotive Restoration

When repairing old vehicles or hot rods, the choice between mild steel, galvanized steel, and stainless steel often boils down to these key differences:

  1. Corrosion Resistance:
    • Mild Steel: Susceptible to rust and corrosion without protective coatings. Often needs to be treated or painted to prevent rust.
    • Galvanized Steel: Coated with zinc to prevent corrosion. Better suited for areas exposed to moisture or harsh conditions.
    • Stainless Steel: Highly resistant to rust and corrosion due to its chromium content. Ideal for environments where rust resistance is crucial, but can be more expensive.
  2. Strength and Durability:
    • Mild Steel: Adequate for general repairs and welding but can be less durable in harsh environments.
    • Galvanized Steel: Similar strength to mild steel but with added corrosion resistance. Less prone to rust when exposed to elements.
    • Stainless Steel: Generally stronger and more durable, with excellent tensile strength. Ideal for structural components and high-stress areas.
  3. Workability:
    • Mild Steel: Easier to cut, weld, and shape. Preferred for custom fabrication and repairs.
    • Galvanized Steel: More challenging to weld due to the zinc coating, which can produce toxic fumes. Requires special techniques for welding.
    • Stainless Steel: Harder to work with due to its toughness and tendency to warp during welding. Typically requires specialized equipment and techniques.
  4. Cost:
    • Mild Steel: Generally the most cost-effective option, making it suitable for budget-conscious repairs.
    • Galvanized Steel: Slightly more expensive due to the coating but offers better longevity in exposed conditions.
    • Stainless Steel: The most expensive of the three, justified by its superior durability and rust resistance.