Material selection is always a trade-off — no material wins on every axis, so the goal is the best balance for your requirements. Start by ranking what actually matters for the part.
| Property | Question it answers |
|---|---|
| Strength / stiffness | Will it carry the load without yielding or flexing? |
| Density (weight) | Does weight matter (aerospace, automotive)? |
| Corrosion resistance | Will it see moisture, chemicals, or salt? |
| Cost | Raw material and processing cost |
| Manufacturability | Can it be machined, cast, welded, or molded easily? |
| Temperature | Will it see heat or cold that changes its behavior? |
A practical approach
List your hard requirements (must not corrode, must survive 200°C, must cost under X), use them to eliminate whole material families, then compare the survivors on the properties you care most about. Engineers often use specific strength (strength-to-weight) when weight is critical, which is why aluminum and titanium dominate aerospace despite steel being stronger in absolute terms.
Frequently asked questions
Most important material property? It depends on the part — define your requirements first, then rank.
What is specific strength? Strength divided by density — useful when weight matters.
Why not just pick the strongest material? Cost, weight, corrosion, and manufacturability often matter more than peak strength.