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This manufacturing materials guide helps engineers choose materials for CNC and molding with confidence—covering CNC aluminum grades 6061 vs 7075, tolerances after anodize/EN, GB/ASTM/JIS equivalents, machinability notes, and downloadable tables/calculators. It’s the hub that links to our process-specific pages (5-Axis CNC, Swiss Turning, Injection Molding, 3D Printing, Sheet Metal).
Picking a material shouldn’t take a dozen tabs and guesswork. This guide puts everything you need in one place—so you can choose a grade, predict how finishing will change your fits, and move to production with confidence.
Clear answers by process. Whether it’s CNC, Swiss-type turning, injection molding, sheet metal, or 3D printing, we show which materials work best—and why.
Fit after finish, not before. Realistic tolerances after anodize/EN/electropolish, plus a quick finish-impact calculator to size critical IDs/threads right the first time.
Proof you can read. Sample MTC/PMI, CMM snapshots, and SPC/Cpk excerpts—evidence you can put in a quality file, not marketing fluff.
Downloadables you can keep. GB–ASTM–JIS equivalents, comparison tables, inspection plan templates, and an RFQ checklist (CSV/XLSX).
Find the right manufacturing material—6061 vs 7075, plastics & steels; real tolerances after anodize/EN; GB/ASTM/JIS equivalents; downloadable tables & templates (2025).
| Grade | Strength | ⚙ Machinability | ✨ Anodize | 📏 Tolerance (typical) | Symbol keywords |
|---|---|---|---|---|---|
| 6061-T6 | ★★ | ★★★ | ✓ Type II | ±0.01–0.05 mm | ✓ weldable · ✨ anodize · 📈 Cpk ready |
| 7075-T6 | ★★★ | ★★ | ✓ clear (⚠︎ hard) | ±0.01–0.03 mm | 🧯 stress-relief · 🔧 post-ream · ⚠︎ SCC risk |
| 5052-H32 (sheet) | ★ | ★★★ | ✓ | ±0.05–0.10 mm (sheet) | ✓ bendable · ✨ anodize · 💲 cost-friendly |
| 2024-T351 | ★★★ | ★★ | ⚠︎ | ±0.01–0.04 mm | ✈ fatigue · ⚠︎ corrosion care · EN coat |
| Grade | 🛡 Corrosion | ⚙ Machinability | Weldability | Finish | 📏 Tolerance (typical) | Symbol keywords |
|---|---|---|---|---|---|---|
| SS303 | △ | ★★ | ○ | 🧪 Passivate | ±0.02–0.05 mm | ✓ free-machining · ⚠︎ chloride |
| SS304 | ○ | ★–★★ | ✓ | 🧪 Passivate | ±0.02–0.05 mm | ✓ general · 🧪 passivate |
| SS316L | ◎ | ★ | ✓ | 🧪 Passivate / ✨ Electropolish | ±0.02–0.05 mm | 🩺 medical · 🌊 chloride-proof |
| Material | ⚙ Machinability | Burr tendency | Finish | 📏 Tolerance (typical) | Symbol keywords |
|---|---|---|---|---|---|
| Brass C3604 | ★★★ | low | ✨ EN/Ni/Au | ±0.01–0.02 mm (Ø<6 mm) | ✓ Swiss first-choice · 📈 Cpk≥1.67 |
| Copper C110 | ★★ | med (smear) | ✨ EN/Tin | ±0.02–0.05 mm | 🔪 sharp tools · 🛢 rich oil |
| Te-Copper C14500 | ★★★ | low | ✨ EN | ±0.02–0.04 mm | ✓ free-cutting · ⚙ improved chips |
| Polymer | Dimensional stability | Moisture | Optics/Polish | Heat | 📏 Tolerance (typical) | Symbol keywords |
|---|---|---|---|---|---|---|
| POM (Acetal) | ○ good | low | ✨ polishable | ○ | ±0.02–0.10 mm | ✓ gears/sliders · 💧 low uptake |
| PC | ○ | low–med | ✨ hard-coat; polish | ○ | ±0.02–0.10 mm | ⚠︎ stress crack · 🛡 hard-coat |
| PMMA | ○ | low | ✨ Ra 0.4–0.8 μm | △ | ±0.02–0.10 mm | 🔍 optical · ⚠︎ brittle |
| PA6/66 | △ | high | — | ○ | ±0.05–0.15 mm | 💧 condition · ⚠︎ drift |
| PEEK | ○ | low | ✨ polish | ◎ | ±0.05–0.15 mm | 🔥 high temp · 🧱 anneal |
| PTFE | △ | none | — | ◎ | ±0.05–0.20 mm | 🧼 low friction · ⚠︎ creep |
| Finish | Nominal deposit per side | Size effect | Action tag (symbol keyword) |
|---|---|---|---|
| Type II anodize | ~5 μm/side | OD ↑; ID ↓ | 🔧 post-ream / 🧷 mask |
| Hard anodize (III) | 12–25 μm/side | OD ↑; ID ↓ | 🛡 protect threads · 🔧 finish-after |
| Electroless Nickel (EN) | 5–10 μm/side | Uniform build | 📐 pre-size · 🔧 hone/ream |
| Electropolish (SS) | −5–15 μm | Material removal | 📏 re-verify · ✨ better Ra |
ASTM Standards · ISO Standards · JIS (JSA) · European Standards (CEN/CENELEC)
| Material | ASTM ≙ | JIS ≙ | EN ≙ | GB ≙ | Symbol keywords |
|---|---|---|---|---|---|
| Al 6061-T6 | 6061-T6 | A6061-T6 | EN AW-6061 | GB 6061-T6 | ≙ equivalents · ✨ anodize |
| Al 7075-T6 | 7075-T6 | A7075-T6 | EN AW-7075 | GB 7075-T6 | ≙ equivalents · 🧯 stress-relief |
| SS304 | 304 | SUS304 | X5CrNi18-10 | 06Cr19Ni10 | 🧪 passivate |
| SS316L | 316L | SUS316L | X2CrNiMo18-14-3 | 022Cr17Ni12Mo2 | 🧪 passivate · ✨ electropolish |
| Brass C3604 | C36000 | C3604 | CW614N | H59/H62 | ⚙ free-cutting |
| Copper C110 | C11000 | C1100 | CW004A | T2 | ⚡ thermal/electric |
| Family | Typical tier | Notes | Symbol keywords |
|---|---|---|---|
| Aluminum (CNC) | ±0.01–0.05 mm | 7075 often 🔧 post-ream after anodize | ✨ Type II · 🧯 stress-relief |
| Stainless (CNC) | ±0.02–0.05 mm | 316L slower; 🧪 passivate | ✨ electropolish |
| Brass (Swiss) | ±0.01–0.03 mm | Ø<6 mm holds ±0.01–0.02 | 📈 Cpk≥1.67 |
| Copper (CNC) | ±0.02–0.05 mm | Control smear/burr | 🔪 sharp tools |
| Tool steel (ground) | ±0.01–0.02 mm | HT then grind | 🛠 grind-to-fit |
| Plastics (CNC/mold) | ±0.02–0.15 mm | POM stable; PA/PTFE wider | 💧 condition · 🧱 anneal |
1) 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.
2) 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. See the Regional Equivalents – Cue Card (PDF) on this page.
3) 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.
4) 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. PA6/66 requires moisture conditioning; PTFE has creep—expect ±0.05–0.20 mm. We’ll advise feature-level tolerances per material.
5) 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. Ask for a redacted sample pack to review before PO.
6) What’s in stock and how fast can I get prototypes?
Typical stock: 6061/7075, SS304/316L, C3604, C110, C45E, H13; plastics: POM, ABS, PC, PMMA, PA6/66 (PEEK in small lots). Prototypes: metals 5–7 working days, engineering plastics 7–10. Special grades usually add +7–15 days; we suggest acceptable equivalents to de-risk.
7) 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), qty & cadence, packaging and compliance. Use our Materials RFQ Checklist (XLSX) and Inspection Plan Template (XLSX).
8) 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.
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