Custom Precision Copper CNC Turned Parts
Overview
Shaft diameters, bores and end faces on copper shafts, sleeves and contact terminals need to mate around a common rotational datum. XCM CNC provides CNC turning of copper parts, including shoulders, grooves and drawing-specified threads, with inspection planned around critical fits and runout requirements. The MOQ is 1 piece, and typical lead time is 10-15 days depending on part complexity and quantity. Submit drawings, the copper grade and temper, critical dimensions and quantity for a quote.
Key Capabilities
- Materials: Copper grades specified by drawing, including oxygen-free copper when required
- Tolerance: +/-0.003 mm (+/-0.00012 inch), IT5 or IT6 accuracy, +/-0.01 mm shaft/bore fits; h6/H7 available
- Surface Finish: Ra 0.8 um on turned outside diameters; Ra 1.6 um on bored holes; contact surfaces confirmed by drawing
- GD&T: 0.012 mm coaxiality for shaft/bore features, 0.012 mm shaft runout, and 0.006 mm roundness; datum and setup by drawing
- Max Size: Turning diameter up to diameter 1250 mm at 2000 mm length; diameter 1200 mm is a conservative option with clearance reserved
- Surface Treatment: Bare copper or electroplating (3-20 um film thickness); plating allowance considered on contact faces and fits
- Thread: Internal threads from M1.4, external threads from M2.0; go/no-go or ring gauge inspection for functional threads
- Precision Limit: +/-0.003 mm on small precision parts under 100 mm; 0.006 mm roundness on shaft and bore fit features
Copper Turned Shafts with Coaxial Fits
Bearing journals, contact sections and coupling seats on stepped copper shafts must share a common axis. Coaxiality capability for shaft and bore features is 0.012 mm, and shaft circular runout capability is 0.012 mm, depending on datum selection and inspection methods. Identify the datum outside diameter and measurement locations on the drawing. Straightness and fixturing become more influential as shaft length increases and require evaluation together.
Copper Sleeve Bores and Roundness Control
The outside diameter and bore of a copper sleeve jointly determine its fit. Roundness and the relationship between these surfaces affect assembly. Roundness capability is 0.006 mm on suitable features. Bores can be specified to H7/H8 or +/-0.006 mm, and dimensions of precision mating surfaces can be evaluated down to +/-0.003 mm. IT5 or IT6 grades depend on drawing features and the process route.
Copper Turning for Grooves and Threads
The minimum turned groove width is 0.5 mm, suitable for retaining-ring and seal grooves. Internal threads start at M1.4 and external threads at M2.0. Functional threads can be checked with go/no-go or ring gauges. Copper is relatively soft, making edge burrs and thread damage more likely. Specify edge-breaking and thread appearance requirements on the drawing.
Copper Turned Surface Finish for Contact Parts
Turned outside diameters can achieve Ra 0.8 um, while bored holes achieve Ra 1.6 um. These values apply to different machined surfaces. Specify the material grade, mating dimensions and surface-protection method together for copper contact parts. Conductivity and contact resistance depend on material and condition, cannot be inferred from surface roughness, and require a separately defined acceptance basis.
Specifications
| Product Name | Custom Precision Copper CNC Turned Parts |
|---|---|
| Manufacturer | XCM CNC |
| Factory Location | Shenzhen, Guangdong, China |
| Quality System | ISO 9001, ISO 13485, IATF 16949, GJB9001C |
| Machining Process | CNC turning |
| Material | Copper |
| Material Grade | Copper grade and temper specified by customer drawing; oxygen-free copper only when specified |
| Tolerance | +/-0.003 mm on precision features; IT5 or IT6 for drawing-defined features; +/-0.01 mm shaft/bore fits; h6/H7 available |
| Surface Roughness | Ra 0.8 um on turned outside diameters; Ra 1.6 um on bored holes |
| Surface Treatment | Bare copper or electroplating 3-20 um film thickness; plating allowance on contact faces and fits |
| Application | Copper shafts, sleeves, terminals, contact pins, and connector sleeves |
| Key Features | Turned diameters, bores, shoulders, grooves, threads, and reference faces as specified |
| Critical QC Requirements | Drawing datums, coaxiality or runout, roundness, fit dimensions, thread standard and effective depth, turned surface finish, and edge acceptance |
| MOQ | 1 Piece |
| Typical Lead Time | 10-15 business days after drawing review |
| Drawing Formats | STEP, IGS, DWG, PDF, X_T |
Applications
Rotational Connection Terminals for Power Transmission and Distribution
Copper terminals and rotary contacts in power distribution equipment use copper conductivity to carry current. Turned shoulders and end faces provide contact surfaces for busbars or bolted connections. Step deviations and burrs on contact faces change the actual contact area, so drawings must define contact-face requirements and the copper grade.
Conductive Slip-Ring Shafts and Sleeves
A slip-ring shaft and conductive sleeve must mate coaxially with bearings, brushes or rings, with shaft diameters, bores and end faces referenced to the same axis. Excessive roundness error or runout can destabilize contact during rotation. Define datums, roundness and runout requirements on the drawing. Conductive performance depends on the specified material.
Cylindrical Connector Housings
A cylindrical connector housing and threaded connector sleeve primarily feature outside diameters, bores and threads. Threads and end mating surfaces determine smooth engagement and locking. Thread standards and effective depths follow the drawing, and functional threads are inspected with go/no-go or ring gauges. Connector drawings define dimensions for sealing and electrical contact surfaces.
Welding Electrode Caps and Contact Tips
A welding electrode cap and welding contact tip deliver current to the working point while removing some heat. Copper electrical and thermal conductivity suit these functions. Outside diameters, end faces and axial holes are rotational features suitable for turning. These parts commonly use copper alloys, so specify the grade, temper and actual operating conditions on the drawing.
Circular Connector Contacts for Communications Equipment
A circular connector contact and coaxial contact sleeve are small parts whose outside-diameter, mating-end-face and coaxial-bore deviations directly affect insertion and withdrawal fits. Critical dimensions on small precision parts under 100 mm can be evaluated at +/-0.003 mm. Actual contact geometry and electrical criteria depend on the specified grade and connector drawings.
Why Choose Us
Quality Systems and Inspection Equipment for Rotational Parts
Factory quality systems cover ISO 9001, ISO 13485, IATF 16949 and GJB9001C. Equipment includes DMG, Mazak, Matsuura and Brother, with turning supported by a Mazak I-100S turn-mill center and large CNC lathes. Roundness and coaxiality of copper shafts, sleeves and terminals can be inspected using CMMs and roundness testers.
Machining Support from Small Connectors to Large Parts
Machining coverage extends from small connector contacts to shafts and sleeves up to 2000 mm long. Common copper features such as shaft diameters, bores, shoulders, grooves and threads can be quoted together against drawings. Long parts require separate evaluation of straightness and fixturing.
Equipment Matched to Rotational-Feature Accuracy
Machines are selected from four equipment tiers from mainland China, Taiwan, Japan, and Europe and the United States according to part and operation accuracy requirements, balancing quality and cost. Mating and non-mating surfaces on copper shafts and sleeves require different accuracy. Matching equipment accordingly focuses expenditure where it is needed.
Inspection Reports and Material Certificates according to the Order
Roundness, runout and mating dimensions can be inspected against drawing datums. CMM and FAI reports can be supplied according to order requirements, including the customer’s report format. Material certificates can be provided according to the order where copper grade traceability is needed.
Sample Approval before Production
Samples can first verify shaft and bore fits, threads and edge condition before approved parts proceed to batch production. Samples usually take 3-7 days. An NDA can be signed as needed when project information requires confidentiality.
FAQ
How should I define runout on a copper turned shaft?
Shaft circular runout capability is 0.012 mm, and face runout capability is also 0.012 mm. Identify the rotational datum and measurement locations on the drawing. Long shafts require separate evaluation against length and fixturing.
How thin can a turned copper sleeve be?
Minimum wall thickness is evaluated at the metalworking capability of 0.5 mm, which requires blank pretreatment, stress-relief aging and optimized machining parameters. Thinner walls are more sensitive to clamping pressure, affecting roundness. Identify surfaces that cannot be clamped or marked, together with roundness and bore acceptance requirements, on the drawing.
Which copper grade and temper suit a terminal or contact pin?
The grade and temper should be determined by conductive function, geometry and assembly requirements, usually specified by the designer on the drawing. We machine to drawings and do not assume pure copper or oxygen-free copper. Define the acceptance or test basis for conductivity, contact resistance or service-life criteria. Material certificates can be supplied according to the order for grade traceability.
Can you turn grooves and threads on copper contact parts?
Yes. Minimum turned groove width is 0.5 mm, with internal threads from M1.4 and external threads from M2.0. Specify the thread standard, effective depth, fit class and burr requirements for quotation. Copper is relatively soft, so edge condition must also be defined for acceptance.
How can bare copper be protected after machining?
Bare copper oxidizes and discolors over time. Whether plating is needed depends on the operating environment and contact requirements. Coating thicknesses of 3-20 um change mating dimensions and contact faces, so state whether dimensional acceptance applies before or after plating. Packaging uses foam plus cartons or wooden cases according to the order.
What do you need to quote a copper turned part?
Provide 2D/3D drawings, the copper grade and temper, critical fit and runout requirements, quantity and intended use. STEP, IGES, STP, DWG or dimensioned PDF files are accepted.
How long does a copper turned-part prototype take?
Samples usually take 3-7 days depending on part complexity and quantity. Batch production follows sample approval, with typical production lead times of 10-15 days.
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.
