When this applies
- The original material is unknown or unmarked
- A part failed and material may be the cause
- The original material is no longer available
- You need a cost or availability alternative
Identifying an unknown material
Shops and labs can narrow material quickly: magnetic response, density, hardness, spark testing and, where it matters, alloy analysis. Combine that with what the part does — a wear bushing, a sealing face, a structural bracket — to reach a defensible choice.
- Hardness testing on a non-critical surface
- Alloy analysis where the grade is critical
- Function and environment as corroborating evidence
- Any marking, casting number or colour coding
When to change material deliberately
Repeat failures, corrosion, galling or unavailability all justify a change. Say so in the enquiry: shops will often propose a better-suited grade if they understand the failure mode and the environment.
Availability drives lead time
A grade nobody stocks in your size adds weeks. Ask whether a stocked equivalent meets the requirement — on urgent work it is frequently the difference between days and a month.
RFQ checklist
Include these in your request and suppliers can quote without a round of questions.
- Known or suspected material
- Operating environment: temperature, chemicals, wear, load
- How the previous part failed
- Whether certification is required
- Whether an equivalent stocked grade is acceptable