Material comparison

Compare equivalent property data

Use the same property definition and test conditions for each candidate. Yield strength, tensile strength, and allowable design stress are not interchangeable. Grade, heat treatment, temperature, and loading direction can matter more than the general material name.

Read specific properties carefully

Specific stiffness and specific strength divide the entered property by density. They help compare weight-related tradeoffs, but do not redesign the part's section or check buckling, fatigue, corrosion, or manufacturing suitability. A lighter fixed-volume option may need different dimensions to do the same job.

Comparing candidates without a single score

For a fixed volume, a material with half the density has half the mass. That does not mean it can replace the original material in the same geometry: stiffness, strength, temperature behavior, and manufacturing requirements may differ. Specific stiffness divides elastic modulus by density, while specific strength divides the chosen strength measure by density. Each ratio answers a narrower question than overall suitability.

Begin with one consistent source of property definitions. A yield strength for one candidate should not be compared with an ultimate tensile strength for another as though they were identical criteria. Record material condition and direction when those affect the property, particularly for composites and processed stock. If a candidate needs a larger section to meet a stiffness target, compare the redesigned mass rather than the original fixed-volume mass. The table is most useful for eliminating unsuitable assumptions and organizing tradeoffs. Cost, corrosion resistance, fatigue, availability, and joining requirements may still determine which material is practical for the finished part.

Formula

Mass = density × volume. Specific stiffness and strength divide the property by density.