High-Precision Stainless Steel CNC Machined Parts Supplier
Overview
XCM CNC provides high-precision stainless steel CNC machining focused on sealing faces, tight-fit surfaces, hole locations, and thread inspection for valve bodies, instrument housings, and corrosion-resistant fittings.
Because stainless steel brings work-hardening behavior, passivation rechecks, and O-ring groove control into the process, fixturing, stock allowance, roughness targets, and inspection methods are confirmed before sample or batch machining starts. The factory runs under ISO 9001, ISO 13485, IATF 16949, and GJB9001C systems, with MOQ starting from 1 piece.
Key Capabilities
Machining Parameters and Tolerances
- Materials: Stainless Steel 304, 316, 316L
- Tolerance: +/-0.003 mm (+/-0.00012 inch), IT5 or IT6 accuracy, +/-0.01 mm shaft/bore fits; h6/H7 available
- Surface Finish: Ra 3.2 um milled, Ra 0.8 um turned, Ra 0.4 um ground, Ra 0.2 um polished
- GD&T: Flatness 0.02 mm, concentricity 0.012 mm, position 0.015 mm, cylindricity 0.011 mm, circular runout 0.01 mm
- Max Size: 3-axis milling 3000 x 1600 x 1400 mm; turning diameter 1200 x 2500 mm
- Surface Treatment: Passivation (ISO 15734), bead blasting 80#-220#, polishing (mirror/bright/matte)
- Thread: Internal M1.4 min, external M2.0 min, max M220; NPT/BSP/G/PT pipe threads; depth 4xD
- Precision Limits: +/-0.003 mm on evaluated features, roundness 0.006 mm, profile 0.02 mm on 5-axis surfaces, position 0.015 mm on hole patterns
Precision Tolerance Limits for Stainless Steel CNC Machining
Selected small precision features can be reviewed around +/-0.003 mm, while roundness around 0.006 mm suits bearing seats and precision bores, and concentricity around 0.012 mm suits stepped diameters and shaft-bore fits. Bore tolerances can follow H7 around +/-0.006 mm and shafts can follow h6 around +/-0.005 mm when the drawing and structure support it. Because stainless steel work hardens, cutting parameters and tool strategy must be aligned with the precision target.
Full GD&T Parameter Control on Stainless Steel Parts
Geometric control can cover flatness around 0.02 mm, parallelism around 0.03 mm over 1030 mm datum length, perpendicularity around 0.02 mm over 1000 mm, position around 0.015 mm for hole groups, and profile around 0.02 mm on freeform surfaces. Straightness and symmetry checks can also be applied where the drawing requires them. Sealing faces, hole groups, and locating datums are reviewed together so the inspection method matches assembly intent.
Surface Roughness Grading for Functional Stainless Features
Stainless roughness levels are usually divided by function: regular milled faces around Ra 3.2 um, fine-milled faces and bores around Ra 1.6 um, turned diameters around Ra 0.8 um, ground faces around Ra 0.4 um, and polished faces around Ra 0.2 um. Sealing faces are often controlled around Ra 0.8 um together with flatness and groove geometry, while visible faces may need both Ra 1.6 um and texture consistency.
Inspection Equipment for Precision Stainless Verification
Hexagon CMM is used for position, concentricity, profile, and flatness checks on critical stainless parts. WanHao VMS-3020G 2.5D optical measurement supports fast checks on planar features and small hole groups, TRIMOS 600L supports height-based checks, and roughness testing verifies Ra values on sealing and fit surfaces. Thread inspection follows go and no-go gauges or ring gauges, and report format can be aligned to customer requirements.
Specifications
| Product Name | High-Precision Stainless Steel CNC Machined Parts |
|---|---|
| Manufacturer | XCM CNC |
| Factory Location | Shenzhen, Guangdong, China |
| Quality System | ISO 9001, ISO 13485, IATF 16949, GJB9001C |
| Machining Process | Precision CNC milling, CNC turning, boring, reaming, multi-side machining |
| Material | Stainless Steel |
| Material Grade | 304, 316, 316L by corrosion and drawing requirement |
| Precision Tolerance | +/-0.003 mm for selected small precision features after review |
| Surface Roughness | Ra 1.6 um machined surfaces, Ra 0.8 um sealing faces by requirement |
| Surface Treatment | Passivation, polishing, protected critical surfaces by drawing requirement |
| Inspection | CMM, thread gauge, roughness tester, dimensional inspection by order requirement |
| Application | Sealing valve bodies, instrument housings, precision fittings, corrosion-resistant flow parts |
| Key Features | Sealing faces, precision bores, threads, O-ring grooves, coaxial mating surfaces |
| Critical QC Requirements | Datum definition, CMM inspection, roughness verification, post-passivation recheck |
| Batch Range | Prototype to repeat precision batches by drawing review |
| MOQ | 1 Piece |
| Typical Lead Time | 10-15 business days after drawing review |
| Drawing Formats | STEP, IGS, DWG, PDF, X_T |
| Material Certificate | Material certificate and passivation report by order requirement |
Applications
Sealing Valve Bodies and Pump Seats for Chemical Fluids
Typical Parts: Sealing valve body, pump sealing seat
Stainless steel fits valve and pump parts that need corrosion resistance together with stable sealing surfaces. Sealing faces can be reviewed around Ra 0.8 um with flatness around 0.02 mm, while O-ring groove size and post-passivation rechecks are planned into the same route.
Instrument Housings and High-Precision Fittings
Typical Parts: Sensor housing, high-precision fitting
Instrument parts often need corrosion resistance, stable threads, and consistent hole positions in the same stainless component. Hole-group position around 0.015 mm and CMM inspection are better clarified at drawing stage so later assembly error does not accumulate.
Automation Valve Blocks and Flow Channel Parts
Typical Parts: Stainless steel valve block, flow channel plate
Automation fluid modules often use stainless steel to combine corrosion resistance, clean flow paths, and stable sealing grooves. O-ring groove width down to about 1.0 mm, depth tolerance around +/-0.01 mm, deburring, and passivation are reviewed together before reinspection points are assigned.
Precision Sleeves and Locating Flanges
Typical Parts: Precision sleeve, locating flange
Tight-fit sleeves and flanges often need coaxiality, bore accuracy, and mating-surface quality under corrosion-resistant conditions. Because stainless cutting loads rise with work hardening, stock allowance and tool paths need to be controlled early and then verified through CMM and roughness checks on the final features.
Why Choose Us
Datum Definition Comes Before Machining
For high-precision stainless parts, the drawing datum, inspection datum, and fixturing strategy are matched before tolerances are allocated. On sealing faces, hole groups, and coaxial thread structures, a correct datum plan often matters more than nominal machine accuracy alone.
Inspection Plans Are Configured to the Drawing
If a part needs CMM, roughness testing, gauge checks, or a dedicated report, the measurement points and acceptance rules are confirmed at order stage. Inspection files are then built around assembly and acceptance needs instead of relying on a generic template.
Precision Groove Features Are Validated on the First Sample
O-ring grooves, sealing bores, and high-fit sleeves can go through full first-article inspection during the trial cut so groove shape, deburring effect, and surface condition are confirmed before batch machining. Once validated, the same tools and parameters are held for the production route.
Post-Treatment Effects on Precision Stay Traceable
Passivation or polishing usually changes dimensions only at a small scale, but tight-fit surfaces may still need comparison data before and after treatment. Recording those measurements makes it easier to judge whether post-treatment has affected the final tolerance window.
Critical Surfaces Receive Graded Transport Protection
Sealing faces, polished surfaces, and high-fit areas can be protected according to their precision level. Features below about +/-0.01 mm fit range can be isolated with dedicated wrapping layers to reduce shipping damage and rework risk after arrival.
FAQ
What tolerance can you hold for high-precision stainless steel CNC parts?
Selected precision features can be reviewed around +/-0.003 mm, while standard dimensions more commonly follow +/-0.03 mm. The final tolerance level still depends on grade, geometry, fixturing strategy, and surface-treatment scope.
How do you control sealing-face flatness on stainless steel components?
Flatness around 0.02 mm can be reviewed for sealing faces within the appropriate size range, but the exact result depends on part area, thickness, and clamping method. Sealing faces should be checked together with roughness and any required post-treatment condition.
What measurement equipment do you use for precision stainless steel parts?
Main inspection resources include Hexagon CMM, WanHao VMS-3020G optical measurement, and contact roughness testing. Threads are checked with go and no-go gauges, and TRIMOS 600L is used for height-related verification where needed.
How do you manage burrs and groove depth on stainless O-ring grooves?
O-ring groove width can be reviewed down to about 1.0 mm and depth tolerance around +/-0.01 mm, depending on part geometry. Dedicated deburring tools are used to protect groove shape, while sealing-face condition and groove-bottom surface state are checked together.
Can you hold H7 or H8 bores on stainless housings or fittings?
Yes, H7 or H8 bore fits can be reviewed when bore size, depth, grade, and fixturing support that target. Reaming or boring is selected according to structure and drawing requirements rather than applied as a default route.
How does passivation affect dimensional accuracy on precision stainless parts?
The passivation layer is usually small enough that standard tolerances are not affected in practice, but fit surfaces around +/-0.01 mm and tighter are safer to recheck after treatment. Bore size, sealing-face roughness, and key positions are common targets for that reinspection.
Request a CNC Machining Quote from XCM CNC
Send us your drawings. Our team will review the file and reply with a machining quote. MOQ: 1 piece, with competitive low-cost pricing.
Email: [email protected] | WhatsApp: +8618638951317
