CNC machining materials, grade checked before the price
About 30 metal and plastic grades with international equivalents and machining notes. Hard-to-source grade? We propose an equivalent in the quote, for your approval.
- About 30 gradesAluminum, stainless, steel, brass, copper, titanium, plastics.
- Equivalents on every gradeGB, EN, AISI, and JIS names side by side.
- Mill certificates on requestFor the material used in your order.
- Allowance for finish and hardeningPlanned into the grade and the cut.
Start from what the part has to do
Start with 6061 or 6082. Move to 7075 where load or stiffness is critical.
Hardened after rough machining, then ground or wire-cut to size.
316L where chlorides or cleaning agents are present. Passivated after machining.
POM for accuracy, UHMW-PE for wear strips, nylon for impact.
PEEK keeps size and strength at temperature; FR4 for flat insulating plates. See our PEEK machining services.
T2 for conductivity, silver or nickel plated for contacts.
Machined faces polished back to clear. PC for impact, PMMA for clarity.
Titanium for strength and corrosion resistance; 7075 when cost matters.
Grades, equivalents, and what they mean for your part
Equivalents are the nearest common matches in Chinese (GB), European (EN), American (AISI/ASTM), and Japanese (JIS) standards. Where a property is critical, put it on the drawing.
| Grade | Equivalents | Typical use | Machining note |
|---|---|---|---|
| 6061-T6 | EN AW-6061 · A6061 | Brackets, plates, housings, robot flanges | Our most common grade. Clean machining, good anodize. |
| 6082-T6 | EN AW-6082 (AlSi1MgMn) | European drawings, thin-wall flanges, frames | Slightly stronger than 6061; the usual 6xxx grade on EU drawings. |
| 6060 | EN AW-6060 | Housings and profile-based parts | Softer, very good surface for anodizing and plating. |
| 7075-T6 / T651 | EN AW-7075 · A7075 | Grippers, arms, high-load fixtures | Strongest common grade. Not for welding. |
| 2024-T3 / T351 | EN AW-2024 · A2024 | High-fatigue structural parts | Strong but low corrosion resistance; anodize or coat. |
| 5083 | EN AW-5083 · A5083 | Base plates, vacuum and marine parts | Stable plate after machining, weldable. |
| 5052 | EN AW-5052 · A5052 | Covers and sheet-type parts | Gummy in deep pockets; better for sheet and formed parts. |
| Grade | Equivalents | Typical use | Machining note |
|---|---|---|---|
| 303 | 1.4305 · SUS303 · Y1Cr18Ni9 | Shafts, fittings, turned parts | Free-machining. Not for welding, slightly lower corrosion resistance. |
| 304 / 304L | 1.4301 / 1.4307 · SUS304 · 06Cr19Ni10 | General industrial and food equipment parts | Work-hardens: sharp tools and steady feeds. |
| 316 / 316L | 1.4401 / 1.4404 · SUS316L · 022Cr17Ni12Mo2 | Chemical, marine, medical, food contact | Better chloride resistance than 304, tougher to cut. |
| 316Ti | 1.4571 | Welded or heated parts, common on German drawings | Titanium-stabilized 316, machined like 316. |
| 440C | 1.4125 · SUS440C · 9Cr18Mo | Wear parts, valve seats, pins | Machined soft, hardened to drawing (typically HRC 56–60), then ground. |
| Grade | Equivalents | Typical use | Machining note |
|---|---|---|---|
| Q235 | ≈ S235JR · A36 · SS400 | Welded frames, base plates, brackets | Weldable and low cost; specify a coating. |
| 45# | C45 (1.0503) · AISI 1045 · S45C | Shafts, pins, simple gears | Machines well; can be quenched and tempered. |
| 40Cr | 41Cr4 (1.7035) · AISI 5140 · SCr440 | Shafts and gears needing more strength | Quench and temper to drawing hardness. |
| 42CrMo | 42CrMo4 (1.7225) · AISI 4140 · SCM440 | Loaded shafts, fixtures, QPQ wear parts | Tough alloy steel; works well with QPQ and nitriding. |
| Cr12MoV / D2 | ≈ 1.2379 · SKD11 | Punches, cutting and locating inserts | Machined annealed, vacuum hardened, then ground or wire-cut. |
| Grade | Equivalents | Typical use | Machining note |
|---|---|---|---|
| HPb59-1 brass | ≈ CW614N (CuZn39Pb3) · C38500 | Fittings, threaded inserts, frames | Free-cutting: clean threads and sharp edges. See our brass machining services. |
| Other brass grades | To your drawing | Formed or lead-free parts | Grade confirmed at drawing review. |
| T2 copper | ≈ Cu-ETP (CW004A) · C11000 | Bus bars, contacts, heat-transfer parts | Soft and gummy; sharp tools for burr-free edges. |
| Grade | Equivalents | Typical use | Machining note |
|---|---|---|---|
| TC4 | Ti-6Al-4V · Grade 5 (3.7165) | High strength-to-weight parts | Cut slow and cool, with sharp tools. See titanium CNC machining. |
| Other titanium alloys | To your drawing | Pure titanium and other grades | Grade and stock confirmed at drawing review. |
| Grade | Equivalents | Typical use | Machining note |
|---|---|---|---|
| POM | Delrin · POM-C / POM-H | Bushings, slides, guides, gears | Stable and low friction; our most common plastic. |
| PA6 / PA66 | Nylon | Wear pads, rollers, guides | Absorbs moisture: allow for size change. |
| PEEK | Unfilled, glass- or carbon-filled | Insulating, high-temperature, sterilized parts | Holds size at temperature; costly material. |
| UHMW-PE | PE 1000 | Wear strips, conveyor guides, star wheels | Very low friction; soft, so held gently. |
| PTFE | Teflon | Seals, insulators, chemical-resistant seats | Soft; light clamping to hold size. |
| PC | Polycarbonate | Clear covers and guards | Tough; faces polished back to clear. |
| PMMA | Acrylic | Windows and display parts | Very clear; brittle at sharp inside corners. |
| ABS / PP | – | Prototypes, covers, chemical-resistant parts | Low cost and light. |
| FR4 / G10 | Glass-fiber epoxy board | Insulating plates and fixtures | Abrasive: carbide tools and dust extraction. |
No silent substitutions
Grade checked at drawing review
Material, temper, and hardness are read off the drawing before we price. Missing or unclear callouts come back as questions, not guesses.
Equivalents proposed, for your approval
If the drawing grade is hard to source in China, the quote names the equivalent we suggest and why. You decide.
Mill certificates on request
Ask with the quote and we supply the material certificate for the material used in your order.
Allowance for finish and hardening
Anodize thickness, plating, and grinding stock after hardening are planned before the cut.
Finishing and heat treatment by process: secondary processes · Tolerances by process: CNC milling and CNC turning · Roughness by finish: surface finish chart (Ra values)
Three materials, three case notes
304 stainless, SUS430 stainless, and TC4 titanium, each with the method and measured result.
48 pcsThin-wall 304 conical rings
Walls that distort in a normal chuck. A dedicated fixture turned in-house, two operations per ring.
Read the case note
100 pcsSUS430 motor housings
A 10 µm band on Ø8. Micrometer readings 7.987 and 7.988 mm against 7.98–7.99.
Read the case note
30 pcsTC4 titanium prototypes
±0.05 mm on diameters and hole positions, Ra 1.6, M2 threads and Ø1.6 mm holes.
Read the case noteCommon questions about CNC materials
6061 or 6082 aluminum covers most plates, brackets, and housings. Use hardened steel such as 42CrMo with QPQ, or Cr12MoV / D2, for fixtures and wear parts, 304 or 316L stainless where parts are washed down, and POM or UHMW-PE for slides and guides.
Yes. We machine to the grade on your drawing, such as EN AW-6082, 1.4404, 42CrMo4, or SUS303. Where that grade is hard to source in China, we propose the nearest equivalent in the quote for your approval.
Yes, on request. Ask with your RFQ and we supply the material certificate for the material used in your order.
Yes. Parts in Cr12MoV / D2, 440C, or 40Cr are machined before hardening, then hardened to your drawing and ground or wire-cut to final size. 42CrMo can also be machined and then QPQ treated for wear and corrosion resistance.
POM and PEEK are the most dimensionally stable. Nylon absorbs moisture and changes size, and UHMW-PE and PTFE are soft, so we clamp them gently and confirm achievable tolerances at drawing review.
Drawing review with manufacturability feedback in the quote, including the grade and finish, a free first-article inspection report, and our remake guarantee: parts that do not meet your drawing are remade at our cost, with freight paid both ways. We reply by email within 24 hours and on WhatsApp within 12 hours.
Not sure about the grade? Send the drawing.
We check the material, finish, and hardness before the price, and suggest an equivalent if needed. Free first-article report on your first order. Email reply within 24 hours, WhatsApp within 12 hours.
Send Your Drawing