Exact grade & condition
Keep suffixes and the specified standard in the RFQ. A broad “stainless steel” description is insufficient for material purchasing.
Metal / CNC MATERIALS
Stainless Steel CNC Machining
CNC milled and turned stainless steel parts to your drawing. Our regular work includes 300-series stainless steels, 430 and 430F.
CNC milling & turning · Drawing-based orders
Why keep 303, 304 and 316 separate?
Machinability, corrosion requirements and the purchase specification can point to different grades. A free-machining stainless designation should not replace a corrosion-driven specification simply because it cuts more easily. Keep L and F suffixes, the stock condition and the required finishing treatment in the review.
01 / MATERIAL SPECIFICATION
Stainless steel grades & conditions.
Match the full designation on your drawing. Frequent machining experience, published project evidence and specifications for review are shown separately.
| Grade / designation | Experience | Include with your drawing | Inquiry |
|---|---|---|---|
| 300 series | Regularly machined | State the exact grade, such as 303, 304 or 316, and any L suffix on the drawing. | Quote grade ↗ |
| 430 | Regularly machined | Specify 430 and the required supplied condition. | Quote grade ↗ |
| 430F | Regularly machined | Specify 430F explicitly; do not omit the suffix or assume substitution with 430. | Quote grade ↗ |
| 304 | Published project | Documented 50-part, multi-face machining project with published CMM excerpts. | Quote grade ↗ |
| SUS431 | Published project | Documented turned parts, partner grinding and bore inspection. | Quote grade ↗ |
| SUS420J2 | Published project | Documented Swiss-type machining in the annealed condition. | Quote grade ↗ |
| 17-4 PH | Specify for review | Include the required material condition and any heat-treatment requirement. | Quote grade ↗ |
OUJI machining experience: confirmed by the company owner, 10 September 2026. Family-level experience does not establish a specific grade, stock condition or customer end use; see individual row and case evidence.
Listed grades do not imply current inventory. Material condition, stock form and documentation are agreed with the quotation.
02 / MACHINING REQUIREMENTS
Make the drawing ready for review.
Focus on the details that change material purchasing, the machining route and finished-part acceptance.
Bores, threads & datums
Identify bore fits, datum order, internal edges and inspection access. Include deburring requirements where internal features matter.
Finishing & documents
Specify passivation or other surface requirements, and the material and dimensional records needed with the order.
03 / PROJECT EXPERIENCE
Stainless steel in the workshop.
Read the actual machining route and evidence for each project. Requirements and individual inspection results retain their original scope.
304 stainless steel
304 Stainless Steel: Multi-Face Datum Control in a 50-Part Run
- Project quantity
- 50 parts
- Production process
- Chinese-built Qiaohong (乔鸿) machining center; 3+2 indexed milling
What this case documents
The order quantity is 50 parts. The published measurements cover the two displayed CMM evaluations. Engineering reviewed and approved the B → C to C → B datum-order change. The ISO-referenced drawing and the ASME Y14.5 program setting are documented separately; the comparison is to the programmed limits. The excerpt does not establish batch-wide acceptance or a sampling plan.
SUS431 stainless steel
SUS431 Precision Parts: 2,000 per Batch, 100% Bore Inspection
- Project quantity
- 2,000 parts per batch
- Drawing requirement
- Three cylindrically ground ODs; stated +0.005 mm process requirement
What this case documents
Batch size, process sequence, the +0.005 mm requirement and 100% borescope inspection are confirmed by OUJI. The photograph documents one displayed outside-diameter reading; it does not establish results for all three precision diameters or dimensional acceptance of the entire batch.
SUS420J2, machined in the annealed condition
Reducing a SUS420J2 Thin-Wall Part Cycle from 10 to 8 Minutes on a STAR SP-23
- Project quantity
- 1,000 parts
- Drawing requirement
- 17.3 ± 0.02 mm
What this case documents
The grade, annealed condition, order quantity and cycle figures come from OUJI internal production records; no material certificate or work order is published. The optical image documents one feature on one inspected part. HV600 is the specified post-heat-treatment hardness; no hardness-test report or batch capability study is published.
ORDER DETAILS
Material, finish and documentation.
Specify the requirements together so the quoted scope matches the finished part you need.
Purchasing
Material certificates ↗
Specify the material records and traceability your order needs.
ManufacturingFinish compatibility ↗
Connect material, coating and final dimensional requirements.
SpecificationGrade cross-reference ↗
Review regional names without assuming an automatic substitute.
Finishing is coordinated through specialist partners. View surface finishing services.
Can 430F be quoted as 430?
Use the exact designation. The F suffix identifies a different purchasing specification; the two names should not be collapsed into a single grade in the drawing or quote.
Does OUJI machine stainless steels beyond the 300 series?
Yes. The owner confirms machining experience with 400-series stainless steels, including regular 430 and 430F work. Published SUS431 and SUS420J2 projects provide more specific process evidence; they do not establish every condition available across the family.
Is a CMM report the same as a stainless material report?
A CMM report records measured dimensions. A material report addresses the supplied metal and its stated tests or conformity. Ask for both when the order requires dimensional results and heat or lot traceability.
DRAWING TO QUOTATION
Have a material on your drawing?
Send the drawing and quantity. We’ll review the material, machining route, finish and inspection requirements together.
Response within 24 hours of receiving complete project details.
Start with what you have.
Open the full request form ↗Details already in your drawing do not need to be repeated. If a material is undecided, tell us what the part needs to do.
See our inspection approach ↗