Q1.
How do you guarantee fit after anodize or EN plating?
We design to the post-finish size. Typical growth: Type II anodize ≈ +5 μm/side, Type III 12–25 μm/side, EN
5–10 μm/side. For tight IDs/threads we mask or post-machine (ream/hone) and verify with CMM. Use our Finish-Impact Calculator
(XLSX) to pre-size features.
See the Finish Impact – Quick Fit Planner and tolerance tiers by family
above for guidance on pre-sizing IDs, ODs and threads.
Q2.
My drawing is JIS/GB only—can you quote in ASTM/EN?
Yes. We propose regional equivalents (GB • ASTM • JIS • EN) during quoting and confirm by MTC (heat/lot, chemistry/mechanicals)
before production. We can attach the agreed cross-reference to your RFQ and PO so sourcing and quality stay aligned.
Use the Regional Equivalents – Cue Card on this page for a quick view of common GB–ASTM–JIS–EN
matches.
Q3.
What tolerances can you hold on Swiss-type turned pins?
On C3604 brass, Ø < 6 mm features can typically hold ±0.01–0.02 mm with the right process window; we target
Cpk ≥ 1.67 for CTQs and provide CMM/SPC snapshots with the lot. Copper and tellurium copper are slightly wider but still suitable
for precision electrical connectors.
For more detail, refer to our Swiss-type turning – non-ferrous picks table and the
Tolerance tiers by family – Reality check section above.
Q4.
Can plastics hold ±0.01 mm? Which polymers are best for fits?
POM/Acetal is the most dimensionally stable for press-fits; PC/PMMA can meet optical finishes (Ra 0.4–0.8 μm) but need stress
control and sometimes annealing. PA6/66 requires moisture conditioning, and PTFE has creep—expect around ±0.05–0.20 mm. We’ll
advise feature-level tolerances per material and geometry.
See the Engineering plastics – stability & finish table above for typical tolerance ranges and behaviour
by polymer family.
Q5.
What quality documents will I receive?
Standard pack: MTC, optional PMI, FAI/ISIR (Hexagon CMM), SPC/Cpk excerpt on
CTQs, COA/COC, and packaging photos/SOP. On request we can share a redacted sample pack so you know exactly what to expect before
PO.
Our materials tables, tolerance tiers and case browsing gallery show how these records
tie back to real projects and inspected parts.
Q6.
What’s in stock and how fast can I get prototypes?
Typical stock: aluminum 6061/7075, stainless SS304/316L, free-cutting alloys C3604, C110, C45E, H13;
plastics: POM, ABS, PC, PMMA, PA6/66 (PEEK in small lots). Prototype lead times are usually 5–7 working days for
metals and 7–10 working days for engineering plastics. Special grades may add +7–15 days; we often suggest
acceptable equivalents to de-risk schedules.
Check the CNC machining & molding material articles,
CNC aluminum grades and stainless steels – process & finish sections to see
which stocked grades best fit your project.
Q7.
What information do you need for a right-first-time quote?
Send STEP + PDF, preferred grade + acceptable equivalents, temper/HT, finish type & thickness (μm), post-finish dimensions that matter, CTQs
& datums, inspection level (FAI / 100% / sampling), quantity & cadence, packaging and compliance requirements. Our Materials RFQ Checklist
(XLSX) and Inspection Plan Template (XLSX) help make sure nothing important is missed.
Use the Finish Impact – Quick Fit Planner and
tolerance tiers by family above when defining critical fits and inspection levels.
Q8.
Do you support aerospace / medical requirements?
Yes—AS9102 FAI-ready, Cpk targets for production, passivation/electropolish for SS316L, lot traceability, and controlled packaging
(trays/VCI/clean pouches). We align the inspection plan to your CTQs and provide all records with shipment so your quality and regulatory teams
can sign off quickly.
Stainless selections in the stainless steels – process & finish table and real examples in
case browsing – precision CNC materials in real projects show how we handle aerospace and medical components in
practice.
