CNC Turned 316L Stainless Steel Dairy Union Fitting 2 Inch Tri-Clamp Ra 0.8μm FDA

This dairy union fitting is machined from Stainless Steel 316L (316L (1.4404)) to ±0.02mm in the critical dimensions, then finished by Ra 0.8μm internal electropolished. It is produced on CNC turning centres that are dedicated to small and medium volume precision work, so every dimension on the drawing is generated by the machine rather than by hand fitting. Typical users are engineers who have already been let down by a supplier that quoted a tolerance it could not hold, and who need the part to fit the first time without sorting or rework on the assembly line.

• Hygienic Internal Finish: Ra 0.8μm internal surface with no crevices supports cleaning in place without bacterial harbourage
• Full Bore Flow: Bore matches the tube internal diameter so there is no step where product can accumulate
• Tri-Clamp Compatibility: 64mm clamp face is machined to the standard profile so gaskets seat without over compression
• Electropolished Wetted Surface: Electropolishing passivates the chromium layer and removes machine marks from the wetted path
• Traceable Documentation: Material certificate with heat number, surface finish readings and 3-A compliance statement

The process route is fixed before metal is cut. Bar stock is verified against the purchase specification and the heat number is logged, then a first article is turned and measured in full. Only after the first article is signed off does the lot run. Critical features on this dairy union fitting are controlled to ±0.02mm with a process capability target of Cpk 1.33 or better, and the operator checks the feature at a defined frequency with the gauge stated on the control plan. Where the drawing calls for Ra 0.8μm internal electropolished, the finishing step is carried out in house and the result is measured, not assumed. Sample parts go to the CMM for full dimensional verification, and the recorded results ship with the lot as a first article inspection report in PPAP level 3 format when a customer program requires it.

Questions are handled by engineers rather than by sales staff. Our team reviews each drawing for manufacturability, flags features that would drive cost without adding function, and proposes the tolerance band that actually matters for the assembly. That review is free and is returned within 24 hours together with a quotation. When a part fails in the field, we ask for the sample back, section it if needed and report what the failure mechanism was, because a supplier that cannot explain a failure cannot prevent the next one.

• Machines: 50+ CNC units including Swiss type lathes, 3, 4 and 5 axis machining centres and turn-mill centres from Citizen, Star, Doosan and Mazak.
• Quality lab: CMM, 2D vision measurement, roughness tester, hardness tester, salt spray chamber and spectral analyser for material verification.
• Team: 15+ mechanical engineers covering DFM review, process design, fixture design and failure analysis.
• Capacity: 500,000+ precision turned parts per month with stable output and on time delivery tracking.
• Quality system: ISO 9001:2015 certified, SGS audited, material traceability from mill heat to finished part.
• Export experience: parts shipped to 30+ countries across North America, Europe, Japan, Korea and Southeast Asia.

Dairy processing lines, brewery transfer piping, pharmaceutical CIP skids, and food grade pump connections.

Parts are degreased, dried and packed so that the surface finish specified above arrives intact. Standard packing is VCI paper or individual PE bag, a partitioned foam tray for form features, and an export grade corrugated carton on a pallet, with the lot number and heat number marked on the outside. Parts are warranted against material and workmanship defects for 12 months from delivery. If a part is found outside the drawing, we replace it at our cost and we pay the return freight for the defective lot. Third party inspection by SGS, BV or TUV can be arranged before shipment at your request, and we work under NDA where drawings are confidential.

Q: Can you certify 3-A compliance? A: We machine to the 3-A dimensional requirements and provide a compliance statement with surface finish data. Formal 3-A authorization is held by the equipment builder, and we support their audit.

Q: Do you electropolish the whole fitting or just the bore? A: Wetted surfaces are electropolished and the exterior is passivated. Full body polishing is available for visible installations.

Q: What gasket material should we use? A: EPDM for most dairy CIP cycles, silicone for high temperature, PTFE for chemical resistance. We can supply gaskets matched to your clamp standard.

Q: How do you verify Ra 0.8μm on an internal bore? A: We use a portable roughness tester with a small probe on sample parts and cut a section on first articles for a full profile report.

Q: How do you confirm the Stainless Steel 316L material before it is machined? A: Every bar is checked against its mill certificate with an optical emission spectrometer before it goes to a machine. If the chemistry does not match the grade, the bar is rejected and returned. The certificate for your lot is filed under the heat number and can be sent with the shipment or on request.

Q: What happens if a delivered part measures outside the ±0.02mm tolerance? A: Send the measurement and the lot number. We check the recorded values for that lot, replace the parts at our cost and cover the return freight. Because each critical feature is recorded during production, we can trace the deviation to a tool wear step, a fixture shift or a gauge issue and correct the process before the next lot runs.

Send a 2D drawing, a STEP file or a sample and you will have a manufacturability review and a firm quotation within 24 hours. Trial orders from a single piece are accepted, so the tolerance claim can be checked on your own assembly before a production order is placed.