Custom Precision Magnesium CNC Turned Parts
Overview
XCM CNC provides precision magnesium alloy CNC turning for lightweight sleeves, stepped shafts and circular housings, including outside diameters, bores, end faces, grooves and threads. Assembly depends on rotational datum relationships between diameters, bores, end faces and threads. Magnesium alloys offer low density and high specific strength and are commonly used for weight-sensitive rotating and connecting structures. Orders start at 1 piece. Support methods for slender or thin-wall parts and dimensional changes after unclamping affect datum selection and are evaluated during quotation.
Key Capabilities
- Materials: Magnesium alloys such as AZ31B and AZ91D; grade, stock form and supply condition depending on drawing and order requirements
- Tolerance: +/-0.003 mm (+/-0.00012 inch), IT5 or IT6 accuracy, +/-0.01 mm shaft/bore fits; h6/H7 available
- Surface Finish: Turned external surfaces Ra 0.8 um; bored internal surfaces Ra 1.6 um; fit surfaces confirmed together with size tolerance and runout
- GD&T: Coaxiality 0.012 mm and roundness 0.006 mm on applicable turned features; datum and inspection method defined on the drawing
- Max Size: Turning diameter 1250 mm at 2000 mm workpiece length; stock form and workholding reviewed per part
- Surface Treatment: Surface protection route and fit-surface dimension state defined by drawing and service environment; no standard film thickness specified
- Thread: Internal threads from M1.4 and external threads from M2.0; go/no-go or ring gauge inspection; engagement length and thread class by drawing
- Precision Limit: +/-0.003 mm on precision features; 0.012 mm runout on shafts and end faces with datum and inspection method stated
Magnesium Turning Datums and Coaxial Fits
Turning relates stepped outside diameters, end faces and bores to a common rotational datum. Shaft diameter tolerances of +/-0.01 mm, h6/H7 fits and IT5/IT6 accuracy grades are planned according to drawings and requirements. Coaxiality of 0.012 mm applies to shaft/bore features and stepped outside diameters and depends on single-setup feasibility, datum selection and inspection methods.
Thin-Wall Magnesium Sleeves
Thin-wall sleeves can spring back after unclamping. Wall thickness, the inside-to-outside diameter ratio and clamping method directly affect roundness, which can reach 0.006 mm on suitable turned features. Minimum metal wall thickness is 0.5 mm. Preventing distortion requires blank pretreatment, stress-relief aging and optimized machining parameters. Minimum feasible magnesium sleeve thickness also depends on alloy, wall span and inspection datums.
Magnesium Grooves and Functional Threads
Minimum turned groove width is 0.5 mm for retaining-ring grooves, seal grooves and O-ring grooves. Minimum thread sizes are M1.4 internal and M2.0 external, checked with go/no-go or ring gauges. Specify effective engagement length and load requirements for load-bearing threads on the drawing.
Long Magnesium Shafts and Turned Surface Finish
Slender shafts can reach a length-to-diameter ratio of 15:1, requiring evaluation of supports such as steady rests or follower rests and staged operations. Turning diameter can reach 1250 mm at a workpiece length of 2000 mm. Turned outside diameters are Ra 0.8 um and bored internal surfaces Ra 1.6 um. Mating features also require dimensional tolerances and runout to be established together. Magnesium blank form and clamping methods are evaluated for each part.
Specifications
| Product Name | Custom Precision Magnesium 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 | Magnesium alloys |
| Material Grade | AZ31B or AZ91D; grade, stock form and supply condition depending on drawing and order requirements |
| Surface Roughness | Turned external surfaces Ra 0.8 um; bored internal surfaces Ra 1.6 um |
| Surface Treatment | Surface protection route and fit-surface dimension state defined by drawing and service environment |
| Max Part Size | Turning diameter 1250 mm at 2000 mm workpiece length; stock form and workholding reviewed per part |
| Application | Lightweight sleeves, stepped shafts, and circular housings |
| Key Features | Turned external diameters, bores, end faces, grooves, threads, and knurling |
| Critical QC Requirements | Coaxiality, roundness, runout, shaft and bore fits, thread gauge inspection, and surface finish by drawing |
| MOQ | 1 Piece |
| Typical Lead Time | 10-15 business days after drawing review |
| Drawing Formats | STEP, IGS, DWG, PDF, X_T |
Applications
Optical Barrels and Focus Rings
An optical barrel and focus ring use inside and outside diameters, shoulder faces and threads to establish alignment along the optical axis. Coaxiality and roundness affect alignment and smooth rotation after assembly. Dimensional stability under operating-temperature changes requires evaluation against grade and material condition.
Locking Rings and Threaded Interface Sleeves for Portable Equipment
A locking ring and threaded interface sleeve require inside and outside threads, end faces and thin cylindrical walls to share one axis. Small threads start at M1.4 internal and M2.0 external and are checked with go/no-go gauges. Thread fit and dimensional change after unclamping thin walls are key concerns.
Robot Joint Sleeves and Drive Shafts
A joint shaft sleeve and drive shaft use journals, bearing seats and end faces as mating datums. Shaft diameter tolerance, circular runout of 0.012 mm and coaxiality are assembly priorities. Magnesium alloys reduce rotating mass. Contact with steel bearings or screws requires galvanic corrosion protection, while loads and wear requirements are evaluated against the drawing.
Automotive Seat Adjustment Knobs and Spacers
An adjustment knob can have straight or diamond knurling with modules of 0.3-1.0 on its outside diameter. A circular spacer instead focuses on the relationship between both end faces and the bore. Connection strength, operating environment and surface protection follow drawings and operating requirements.
Why Choose Us
Quality Systems and Turning Equipment
We operate under ISO 9001, ISO 13485, IATF 16949 and GJB9001C quality systems, with equipment from DMG, Mazak, Matsuura and Brother. Turning equipment includes the Mazak I-100S turn-mill center, Jingshang automatic lathes and Shenyang CK61125X2000 CNC lathe.
Turning Support from Small Connectors to Large Rotational Parts
Our machining coverage extends from small connectors to large structural parts, with turning diameters up to 1250 mm at workpiece lengths of 2000 mm. Turning, boring, threads, grooves and knurling can share defined datums and inspection methods on one drawing. The final dimensional condition of inside and outside mating surfaces is also agreed.
Equipment Tiers Matched to Fit Accuracy
Our equipment spans four tiers from mainland China, Taiwan, Japan, and Europe and the United States. Precision shaft/bore fits and general external surfaces on the same sleeve demand different machine accuracy. Matching equipment to requirements balances machining quality and cost.
Inspection Aligned with Roundness and Coaxial Relationships
Datums for roundness, coaxiality and runout are first defined on the drawing, then measurements use roundness testers, CMMs or other equipment relative to those datums. Material certificates, CMM reports and first-article reports can be supplied according to order requirements.
From Single Prototypes to Batches
Orders start at 1 piece. Prototypes usually take 3-7 days and standard lead time is 10-15 days, depending on part complexity and order quantity. Batch production follows sample approval. An NDA can be signed as needed for drawings.
FAQ
Which magnesium grade and stock condition suit a turned sleeve?
Specify the grade, procurement standard, blank form and supply condition during inquiry. AZ31B is commonly supplied as extruded bar and suits turning from bar stock. AZ91D is more commonly a die-cast blank; state its condition where secondary turning is needed. Material certificates can be supplied according to the order to check actual material against drawing requirements.
How does length-to-diameter ratio affect a magnesium turning quote?
Slender shafts can reach a length-to-diameter ratio of 15:1, requiring evaluation of steady rests, follower rests and staged machining. Thin walls, deep holes, groove locations and threads also affect clamping and inspection plans. Identify these features on the drawing for quotation.
How are roundness and runout checked on magnesium turned parts?
Roundness is checked on a roundness tester. Coaxiality and runout datums are first defined on the drawing, then roundness testers, CMMs or other equipment measure from those datums. Shaft circular runout and face runout capabilities are 0.012 mm. Applicable features and inspection methods are agreed during quotation. Critical-dimension inspection and first-article reports can be supplied according to the order.
How should coating allowance be defined on a magnesium shaft fit?
Define in advance on the drawing whether final mating dimensions apply before or after coating, together with masked locations and the operating environment. Coatings change shaft/bore clearances, and thickness varies by treatment. The dimensional acceptance condition must be established before machining dimensions can be set.
How is magnesium chip and dust safety assessed during turning?
Fine magnesium chips and dust are flammable. Fine chips from finish turning of thin walls present greater risk, so wall thickness, machining allowance and finishing requirements affect machining plans. Safety requirements are established for the project. State wall thickness and allowance during inquiry.
What information is needed to quote a magnesium turned part?
A quote requires 2D/3D drawings, material grade and condition, quantity, tolerances and application requirements. STEP, IGES, STP, DWG or dimensioned PDF files are accepted. A 3D model defines external geometry, while fit tolerances, rotational datums and surface requirements follow dimensioned 2D drawings or PDFs.
When does a magnesium part need turn-mill instead of plain turning?
Turning is sufficient for rotational features such as outside diameters, bores, end faces, grooves, threads and knurling. Radial holes, flats or mounting lugs require milling and drilling capability. The Mazak I-100S turn-mill center has a second spindle and performs turning, milling and drilling. Single-setup feasibility depends on geometry and datums and requires drawing-based evaluation.
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.
