Stainless steel
303 · 304 · 316
303 is the free-machining grade for high-volume turned parts. 304 is the general-purpose grade. 316 adds corrosion resistance for marine, medical and chemical contact.
Quote a stainless partCAPABILITIES / MATERIALS
Materials for CNC turned and mill-turn parts
Stainless steel, brass and copper, aluminum, carbon and free-cutting steel, and engineering plastics, turned in our own factory in Dongguan.
Machined to the grade on your drawing, with a material certificate on request. C45 and 4140 are usually heat-treated in our own factory.
Send a drawing for review
STEP · PDF · DWG · NDA available
First reply within 24 hours on working days (China time)
MATERIALS
Grades we machine, and when to choose them
The notes are general guidance; the grade on your drawing applies.
Brass and copper
C3604 brass · H59 brass (≈ CuZn40) · H62 brass (≈ CuZn37) · C11000 copper
C3604 is the free-cutting brass for high-volume turned parts such as connectors and fittings. H59 and H62 are Chinese standard brasses. C11000 copper is used where electrical or thermal conductivity matters.
- Production case: Thin-Walled Brass Sleeves
- Production case: Brass Laser Bracket
- Brass turned parts: grades, tolerances and finishes
Aluminum alloys
2024 · 5052 · 6061 · 6063 · 7075
6061 is the usual choice for turned parts and anodizes well. 6063 suits cosmetic anodized parts. 2024 and 7075 give higher strength; 5052 resists corrosion. If appearance after anodizing matters, state it on the drawing: the alloy affects the finish.
- Production case: Black Anodized Optical Rings
- Production case: Scratch-Free Anodized Aluminum Sleeves
- Aluminum turned parts: grades, thin walls and anodizing
Carbon and alloy steel
20 steel (≈ 1020) · 45 steel (C45 / 1045) · Q235 (≈ S235JR) · Q345 (≈ S355JR) · 4140
45 steel (C45) and 4140 suit shafts and parts that need hardening. 20 steel, Q235 and Q345 suit general structural parts.
- Heat-treated in our own factory: C45, 4140
Free-cutting steel
12L14 · 1215
12L14 and 1215 machine faster than other steels and are a common choice for high-volume turned parts, usually plated afterwards for corrosion protection.
Quote a free-cutting steel partEngineering plastics
POM (acetal) · Nylon (PA) · PTFE · PEEK · PC (polycarbonate)
POM for low-friction wear parts, nylon for tough parts, PTFE for chemical resistance and seals, PEEK for high temperatures, PC for clear parts. Plastics move more with temperature, so tolerances are confirmed per drawing.
Quote a plastics part
HEAT TREATMENT · FINISHES · CERTIFICATES
From bar stock to finished part
Heat treatment, mostly in-house
We heat-treat C45 and 4140 parts in our own factory; some treatments go to outside specialists, and the quotation states which. State the condition or hardness on the drawing, and which dimensions apply after treatment. We check hardness after heat treatment on a calibrated Rockwell tester.
Finishes through tested suppliers
Anodizing and plating are done by outside suppliers. For parts with cosmetic requirements, we run trial batches at the finishing supplier before production.
How we chose an anodizing supplier
Material certificates
We can supply a material certificate with your parts. Name the certificate type you need, for example EN 10204 3.1, in your inquiry.
Inspection & documentation
YOUR DRAWING
What to state on the drawing
- Grade and standard, e.g. 303, 6061-T6 or C45
- Condition, temper or hardness after heat treatment
- Finish specification and thickness; a colour sample if appearance matters
- Dimensions and threads that apply after finishing
- Surfaces to mask or keep unmarked
- Certificate type you need with the shipment
Send it for review
Every drawing is reviewed by our Technical Director. We reply to every inquiry within 24 hours on working days (China time).
Trial runs from 200 pcs, production from 2,000 pcs.
Send a drawing for reviewBUYER QUESTIONS
Questions about materials and finishes
Can you supply material certificates?
Yes. State the certificate type you need, for example EN 10204 3.1, in your inquiry so it is part of the quotation.
Do you heat-treat parts yourselves?
C45 and 4140 are usually heat-treated in our own factory; some treatments go to outside specialists, and the quotation states which. State the required condition or hardness, and which dimensions apply after treatment.
Who does anodizing and plating?
Outside finishing suppliers. For parts with cosmetic requirements, we run trial batches at the finishing supplier before production. Outside finishing can add time to the lead time; your quotation states the date.
My grade is not listed. Can you still quote?
Usually, yes. Send the drawing with the full material designation; we confirm availability and machinability in the quotation.
Can I ask for a material substitution?
Yes. Name the original specification and the alternatives you would accept. We do not substitute a grade without your written approval.
Can you recommend a material?
Tell us what the part does, its environment and any finish or cost target. We can suggest grades to compare; the final choice stays with your engineering team.
YOUR NEXT PRODUCTION RUN
Send the drawing with
the grade you need.
Include the material, finish and quantity you plan to release. Trial runs from 200 pcs, production from 2,000 pcs.
Or email info@nowcnc.com