High-Precision Carbon Steel CNC Machined Parts Supplier
Overview
XCM CNC provides high-precision carbon steel CNC machining focused on finish-machining order before and after heat treatment, shaft-bore fits, hydraulic bores, and datum control on heavy-load parts.
Critical finish work can run on equipment such as DMG 80mono and Mazak I-100S, with Hexagon CMM support for inspection. Where stress relief, coaxiality, runout, and bore-surface quality matter, we confirm stock allowance, fixturing, and inspection methods before releasing the sample or batch. Standard lead time is often reviewed in the 10-15 day range, sample lead time in the 3-7 day range, and MOQ can begin from 1 piece.
Key Capabilities
Machining Parameters and Tolerances
- Materials: Carbon Steel – Q235, 45#, 1045, 40Cr; grade selected by load rating and heat treatment route
- 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/bored, Ra 0.4 um ground, Ra 0.2 um polished
- GD&T: Flatness 0.02 mm, parallelism 0.03 mm/1030 mm, coaxiality 0.012 mm, runout 0.01 mm, position 0.015 mm
- Max Size: Milling 3000 x 1600 x 1400 mm; turning diameter 1250 x 2000 mm
- Heat Treatment: Quenching, tempering, normalizing, stress relief by drawing review
- Thread: M1.4-M220, NPT/BSP/G/PT, depth 4xD, blind-hole effective depth 50 mm
- Inspection Equipment: Hexagon CMM, WanHao 2.5D video measuring, TRIMOS 600L height gauge, roughness tester, thread gauge
Precision Tolerance Limits on Carbon Steel Features
Selected carbon steel features below 100 mm can be controlled to +/-0.003 mm, and fit faces can be held to similar precision when the route supports it. Shaft diameters can follow h6 around +/-0.005 mm and bores can follow H7 around +/-0.006 mm. Roundness around 0.006 mm and cylindricity around 0.011 mm/1030 mm can also be reviewed depending on whether turning or grinding is used.
Full GD&T Parameter Control for Precision Parts
Typical geometric values include flatness 0.02 mm, perpendicularity 0.02 mm/1000 mm, parallelism 0.03 mm/1030 mm, position 0.015 mm, coaxiality 0.012 mm, circular runout 0.01 mm, total runout 0.012 mm, and profile around 0.02 mm when the feature requires it. Long guide faces can also be reviewed for straightness around 0.01 mm/1030 mm. Datum strategy is confirmed against the process order before cutting starts.
Surface Roughness Grading for Functional Surfaces
Carbon steel roughness can be graded by function, such as Ra 3.2 um on regular milled faces, Ra 1.6 um on precision milled faces, Ra 0.8 um on turned outer diameters or hydraulic bores, Ra 0.4 um on ground faces, and Ra 0.2 um on polished faces. Hydraulic and sealing bores often need bore roughness and flatness to be reviewed together with groove dimensions.
Inspection Equipment for Precision Verification
Hexagon CMM can be used for position, coaxiality, and profile checks, while a WanHao vision system can verify planar hole distribution and small-part geometry. TRIMOS height gauges support step and depth measurement, roughness testers confirm Ra values, and go and no-go gauges or thread rings can check functional threads.
Specifications
| Product Name | High-Precision Carbon 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 | Carbon Steel |
| Material Grade | 45#, 40Cr and other carbon steel grades by load and heat treatment route |
| Tolerance | +/-0.03 mm standard CNC tolerance, critical dimensions by drawing review |
| Precision Tolerance | +/-0.003 mm for selected small precision features after review |
| Surface Roughness | Ra 1.6 um machined mating surfaces, Ra 0.8 um hydraulic or sealing bores by requirement |
| Surface Treatment | Black oxide, zinc plating, rust preventive coating after finish machining by drawing review |
| Inspection | CMM, roughness tester, thread gauge, dimensional inspection by order requirement |
| Application | Hydraulic valve blocks, shafts, bushings, flanges, heavy-duty fit parts |
| Key Features | Hole-shaft fits, hydraulic bores, long shafts, heat-treated finish machining, heavy-load chamfers |
| Critical QC Requirements | Heat treatment sequence, coaxiality or runout check, bore roughness, post-process 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 |
| Heat Treatment | By drawing review |
| Critical Tolerance Control | Heat treatment route and datum transfer reviewed before finish machining |
Applications
High-Fit Valve Blocks and Cylinder Components for Hydraulic Systems
Typical Parts: High-fit valve block, cylinder body part
Carbon steel suits hydraulic systems that need both load-bearing structure and tight bore relationships, especially when heat-treatment order must stay aligned with finish machining. H7 or H8 bores, inner-bore roughness around Ra 0.8 um, and key-bore reinspection should all be defined at the drawing stage before the route is released.
Transmission Shafts, Bushings, and Flange Fits
Typical Parts: Transmission shaft, sleeve bushing
These transmission parts depend heavily on shaft tolerance, coaxiality, and runout control, and carbon steel provides a workable base for both load and later heat-treatment routing. Shaft diameters at h6 or h7 and runout targets around 0.01 mm or 0.012 mm need to be reviewed against datum and process order to avoid excessive rework after heat treatment.
Heavy-Duty Pins and Mating Bore Parts for Construction Machinery
Typical Parts: Heavy-duty pin shaft, mating bore seat
Construction machinery pins and matched bores need to balance load, wear, and assembly precision, and carbon steel is often a practical route for those conditions. Heat-treatment allowance, shaft-bore relationships, and deburring order should be planned together so the inspection plan can focus on the true critical dimensions.
Automotive Transmission and Brake Structure Components
Typical Parts: Transmission structure part, brake connection part
Automotive transmission and brake-related structures often use carbon steel to balance strength with machining control, especially when fit dimensions and surface protection both need to follow the drawing. Final application requirements still depend on the customer drawing, service condition, and industry rules before the heat-treatment or rust-protection route is confirmed.
Why Choose Us
Certified Quality Systems and Imported Equipment
XCM CNC is certified to ISO 9001, ISO 13485, IATF 16949, and GJB9001C, covering quality-system requirements for medical, automotive, and military programs. Production uses DMG, Mazak, Matsuura, Brother, and other machining centers together with Hexagon CMM and 2.5D vision inspection.
Machining Range from Small Connectors to Large Structures
The machining range covers parts from miniature connectors and sensor housings to large structural components. Three-axis milling reaches 3000 x 1600 x 1400 mm and turning reaches diameter 1250 mm with length 2000 mm, so the same supplier can cover both compact precision work and heavy long-format parts.
Tiered Equipment Strategy for Cost and Quality
XCM CNC uses a tiered equipment mix from mainland China, Taiwan, Japan, and Europe or the US. Lower-tolerance operations can run on domestic or Taiwan machines, while tighter precision work can move to imported equipment such as DMG or Mazak to avoid unnecessary high-hour-rate use.
Inspection Planning Confirmed by Project
High-precision carbon steel parts do not use one default inspection template. CMM is applied where coaxiality and position matter, gauges can cover functional holes or threads, and roughness testing can confirm sealing faces. XCM CNC aligns the measurement route, acceptance logic, and report format with the assembly requirement during ordering.
Finish-Machining and Delivery State Confirmed Early
From heat treatment to finish machining to rust-protection packaging, each process step affects the delivered state of a precision carbon steel part. XCM CNC confirms finish-machining positions, rust-protection route, and packaging plan before cutting starts, and long shafts or heavy fit parts can receive extra layer protection to reduce transport damage. NDA support is available when required.
FAQ
What tolerance can you hold for high-precision carbon steel CNC parts?
Selected precision features can be controlled to +/-0.003 mm after review, while regular dimensions typically follow the standard +/-0.03 mm CNC route. The final tolerance still depends on grade, heat-treatment order, part structure, and fixturing method.
What inspection equipment do you use for precision carbon steel parts?
Hexagon CMM can verify coaxiality and hole position, WanHao vision inspection can cover planar geometry, and TRIMOS height gauges can check step depth and perpendicularity. Roughness testers, go and no-go gauges, and thread gauges are added according to the drawing requirement and the inspection scope is confirmed during ordering.
Can you control H7 or H8 bores and h6 or h7 shafts on carbon steel parts?
Yes. H7, H8, h6, and h7 fits can all be reviewed according to the drawing requirement. Whether the route is practical still depends on part size, heat-treatment state, fixturing method, and the selected inspection plan.
What is the MOQ and lead time for precision carbon steel CNC parts?
MOQ starts from 1 piece, sample lead time is often reviewed in the 3-7 day range, and batch lead time in the 10-15 day range. Precision parts may need extra scheduling time if the tolerance level, heat-treatment route, or inspection requirement is more demanding.
What payment and shipping options are available for precision parts orders?
Payment can be arranged by T/T, PayPal, or Western Union. Shipping can use DHL, FedEx, UPS, or sea freight. Precision parts and long shafts can receive separate impact protection with layered foam plus carton or wooden-case packaging selected to the part structure.
How do you manage stress relief before finish machining large carbon steel parts?
Large carbon steel parts are usually reviewed for stress relief and heat-treatment order before final finish machining starts. That helps control dimensional stability on long parts, thick plates, and heavy structures, and the critical datums can then be rechecked by CMM after finishing.
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
