Engineering Guide: How to Select the Right Metal Thickness for Your CNC Machining Project

Why Thickness Selection Matters

In precision machining and sheet metal fabrication, thickness is not just a number —      it is a design decision that directly affects product performance and cost.      Choosing the wrong thickness can compromise:

Weight – product portability and shipping cost
     Stiffness – structural performance and long-term durability
     Corrosion resistance – how the product behaves in different environments
     Manufacturability – whether the design can be produced consistently

One of the most common questions we receive is:
     👉 “Is 1.5mm aluminum strong enough, or should I use 19 gauge steel instead?”
     The answer requires an engineering perspective, not a simple yes or no.

Aluminum vs. Steel: Key Engineering Differences

1. Material Properties

Aluminum (typical alloys: 6061, 5052, 7075)
     Lightweight (density ≈ 2.7 g/cm³), naturally corrosion-resistant and suitable for anodizing or powder coating.      Easier to machine and form, but has lower stiffness (Young’s modulus ≈ 70 GPa).

Steel (mild steel, stainless steel)
     Higher density (≈ 7.8 g/cm³), about 2.5–3 times heavier than aluminum.      Offers greater stiffness (Young’s modulus ≈ 200 GPa), but usually requires coatings such as paint or powder coating to resist corrosion.

2. Thickness Conversion Reference

• 0.064 inch ≈ 1.6mm (commonly used in aluminum panels)
     • 1.5mm ≈ 0.059 inch
     • 19 gauge steel ≈ 1.0mm (U.S. Standard Steel Gauge; values differ for stainless and aluminum)

⚠️ Important note: Gauge is not universal. Always specify thickness in millimeters with material type to avoid ambiguity.

Engineering Performance Considerations

Stiffness & Deflection

Under identical load conditions, 1.0mm mild steel typically deflects 30–50% less than 1.5mm aluminum.        However, certain high-strength aluminum alloys (e.g., 7075-T6) can match or exceed mild steel in performance.

Weight Trade-Off

A 1.5mm aluminum panel is typically 40–50% lighter than a comparable steel panel.        For portable equipment, weight reduction is often more valuable than maximum stiffness.

Design Optimization

Aluminum can achieve required stiffness with ribbing, bends, or extrusion profiles.        Steel is efficient in thin, flat parts requiring rigidity — but adds significant weight.

How Bergek CNC Supports Your Decision

At Bergek CNC, thickness choice is not left to guesswork.        We ensure decisions are backed by data and manufacturing experience:

✔ DFM Review – Every quotation is reviewed by engineers to validate manufacturability and performance.
     ✔ Material Guidance – We compare alloys, coatings, and forming processes to recommend the most cost-effective option.
     ✔ Consistency Guarantee – From prototypes to mass production, our document-controlled process ensures every batch meets your original specification.

This means when you ask, “Is 1.5mm aluminum strong enough?”, our response is backed by engineering data, production experience, and real-world testing — not just an opinion.

Final Thought

Selecting the right thickness is never a “one-size-fits-all” decision.      It is a balance of engineering, cost, and application requirements.

👉 At Bergek CNC, we help clients worldwide make these decisions with confidence —      ensuring that every design is both manufacturable and reliable.