Begin with functional requirements

Material selection should start with the part’s actual job: load path, exposure environment, weight target, mating components, finish requirement and procurement standard. Choosing a material only because it is described as premium often leads to avoidable cost or review questions.

When stainless steel may be the practical choice

Stainless steel is commonly considered when a design needs a durable metal component and the drawing calls for a specified stainless grade. It is used across many industrial, equipment and product applications. The exact grade, condition and any corrosion or surface requirement should be stated on the drawing rather than assumed from the word stainless.

When titanium may be considered

Titanium is often selected where a design requires a particular material specification and a balance of strength, mass or corrosion-related performance. Its suitability should be defined by the application and approved material specification, not by a generic substitution during quoting.

Machining review changes with the material

Different materials influence tool selection, workholding, heat management and the way a part is sequenced. Features such as thin walls, deep cavities, small threads and tight interfaces deserve special review because material choice can interact with geometry.

Include the finish in the same discussion

Post-machining treatment is part of the manufacturing route. A part that needs a particular surface condition, passivation, heat treatment or cosmetic handling should carry that information in the RFQ. For aluminum projects, see our 6061 vs. 7075 guide; for post-processing notes, see anodizing and heat-treatment requirements.

A better material note for an RFQ

• State the exact material grade and condition where the design requires it.
• Identify application factors relevant to the part.
• List finish, cosmetic, corrosion or packaging requirements.
• Mark dimensions and interfaces that are functionally critical.
• Provide quantity and destination alongside the drawing or 3D model.

Use the governing specification

When a project is governed by a material standard, purchase requirement or customer specification, include that reference with the RFQ. ASTM International maintains a standards catalog that engineering teams may use when identifying applicable material requirements.