Materials
Material Selection Guide for Precision CNC Parts
Most material arguments are really arguments about one dominant requirement. Name that requirement first, and the shortlist usually becomes obvious.
Side-by-side
Comparison
| Dominant requirement | First choice | Also consider |
|---|---|---|
| Lowest weight | Aluminum | Titanium (if strength matters) |
| Corrosion / hygiene | Stainless 316L | Titanium Grade 2 |
| Highest strength-to-weight | Titanium (Grade 5) | 17-4PH stainless |
| High-temperature strength | Inconel 625 / 718 | Titanium (moderate) |
| Dimensional stability vs temperature | Invar 36 | Kovar (if glass seal) |
| Glass/ceramic sealing | Kovar | — |
| Maximum density | Tungsten heavy alloy | — |
| Low friction without lubrication | POM / PEEK | PTFE (light load only) |
| Chemical inertness | PTFE / PEEK | PVDF |
| Electrical insulation | Engineering plastics | — |
Decision guide
How to decide
- Start from the single requirement that would make the part fail, not from the material you used last time.
- Where two requirements conflict, decide which one is allowed to give. That decision picks the material.
- Bring the drawing early - a DFM review often shows a geometry change that removes the need for an exotic material.
FAQ
Frequently asked questions
Yes. Send the drawing and the dominant requirement; we will propose materials and flag risk in a DFM review before quoting.
That is the normal case. We rank the requirements with you and pick the material that survives the one that cannot be compromised.
Yes - EN 10204 3.1 certificates are available, and material grade is confirmed by in-house spectrometer verification on critical batches.
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