Custom Precision Magnesium CNC Milled Parts
Overview
Portable instrument housings need reduced weight while maintaining accurate assembly relationships between mounting faces, pocket floors and hole patterns. XCM CNC provides magnesium alloy CNC milling for housing cavities, ribs, mounting faces and hole patterns, suitable for instrument enclosures, camera body frames and lightweight brackets. Orders start at 1 piece. Cavity depth, internal corner radii and hole locations affect tool access and quotation.
Key Capabilities
- Materials: Magnesium alloys such as AZ31B and AZ91D; grade, procurement standard, 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: Standard milled faces Ra 3.2 um; finish-milled mounting and contact faces Ra 1.6 um
- GD&T: Flatness 0.02 mm over up to 1030 x 1030 mm machining area; hole-pattern position 0.015 mm with drawing datums defined
- Max Size: Part length up to approximately 2600 mm on 3-axis milling (machine travel 3000 x 1600 x 1400 mm), depending on fixturing and setup
- Surface Treatment: Magnesium corrosion-protection and appearance requirements defined by alloy and service environment; film thickness allowance on fits agreed before machining
- Thread: Internal threads from M1.4 and external threads from M2.0, inspected with go/no-go or ring gauges; engagement and load requirements by drawing
- Precision Limit: +/-0.003 mm on precision features; 0.5 mm minimum metal wall with blank pre-treatment, stress relief, and optimized machining parameters
Magnesium Cavities and Mounting Faces
Magnesium alloy CNC milling produces cavities, mounting faces and hole patterns in lightweight instrument housings. Their relative positions determine whether circuit boards or lens modules assemble correctly. Flatness can reach 0.02 mm over machining areas up to 1030 x 1030 mm, and hole-pattern position can reach 0.015 mm with drawing-defined datums and inspection scope. Precision features such as mating surfaces can achieve dimensional tolerances of +/-0.003 mm.
Thin-Wall Magnesium Housings
Magnesium alloy housings can combine thin walls, ribs and local mounting pads while retaining space for milling tool access. Distortion of 0.5 mm walls is controlled through blank pretreatment, stress-relief aging and optimized machining parameters. Minimum rib thickness is 0.8 mm, with a height-to-width ratio of 8:1. Feasibility also depends on alloy, span and clamping method.
Magnesium Pocket Access and Internal Radii
Cavity depth and internal radii determine tool access and adequate rigidity. Maximum cavity depth-to-width ratio is 4:1, increasing to 5:1 with extended tools. Minimum internal corner radius for end milling is R0.5 mm. For cavities 40 mm deep, an internal radius of at least R1.0 mm is recommended. Features requiring sharp corners need a design adjustment.
Milled Magnesium Surface and Edge Quality
General milled faces are Ra 3.2 um, while mounting and contact faces can be finish milled to Ra 1.6 um. Specify tool-mark direction and appearance requirements on the drawing. Housing edges can be broken by 0.1 mm, cross-holes can be deburred, and threads must be free of crossed or damaged threads and burrs. Magnesium parts generally require corrosion protection, with the method determined by the operating environment and drawing.
Specifications
| Product Name | Custom Precision Magnesium CNC Milled Parts |
|---|---|
| Manufacturer | XCM CNC |
| Factory Location | Shenzhen, Guangdong, China |
| Quality System | ISO 9001, ISO 13485, IATF 16949, GJB9001C |
| Machining Process | CNC milling |
| Material | Magnesium alloys |
| Material Grade | AZ31B, AZ91D; grade, procurement standard, stock form, and supply condition depending on drawing and order requirements |
| Precision Tolerance | +/-0.003 mm on precision features |
| Surface Roughness | Standard milled faces Ra 3.2 um; finish-milled mounting and contact faces Ra 1.6 um |
| Surface Treatment | Magnesium corrosion-protection and appearance requirements defined by alloy and service environment; film thickness allowance on fits agreed before machining |
| Max Part Size | Part length up to approximately 2600 mm on 3-axis milling, depending on fixturing and setup |
| Application | Lightweight instrument enclosures, camera bodies, and optical mounting frames |
| Key Features | Milled cavities, mounting faces, ribs, and hole patterns |
| Critical QC Requirements | Mounting-face flatness, hole-pattern position, thin-wall distortion, and specified surface finish |
| MOQ | 1 Piece |
| Typical Lead Time | 10-15 business days after drawing review |
| Drawing Formats | STEP, IGS, DWG, PDF, X_T |
Applications
Internal Housings for Portable Electronics
A magnesium electronics housing accommodates circuit assemblies within a limited weight budget. PCB mounting step height and grouped mounting holes determine whether boards are secured evenly. Magnesium suits weight-sensitive handheld structures. Where electromagnetic shielding is required, performance depends on seams, grounding faces and protective treatments and must be verified in complete-equipment design.
Camera Bodies and Optical Mounting Frames
A camera body frame and lens mounting frame typically have windows, lens mounting planes and grouped locating holes. Milling relates geometry, mounting faces and hole patterns to the same design datum, helping verify lens-interface relationships. Magnesium provides weight reduction and some damping. Temperature effects on optical alignment depend on grade and material condition.
Robot End-Effector Sensor Brackets
A sensor mounting bracket and pocketed bracket mount on the robot arm end. Lower mass reduces moving-component inertia. Weight-reduction pockets, mounting faces and hole patterns affect weight, mating contact and sensor position respectively, and can be milled on the same part. Loads, fatigue and contact-media requirements are evaluated against drawings.
Automotive Instrument Panel Bracket Prototypes
An instrument panel bracket and ribbed bracket prototype validate lightweight structures and assembly relationships with surrounding components before production. Samples contain mounting faces, ribs, local pockets and fastening holes. Magnesium supports weight-reduction design validation here. Drawings and the operating environment define fastening interfaces, corrosion protection and testing requirements.
Why Choose Us
Quality Systems and Multi-Brand Equipment
We operate under ISO 9001, ISO 13485, IATF 16949 and GJB9001C quality systems and use equipment from DMG, Mazak, Matsuura and Brother. Machining and inspection can be planned around magnesium housing cavities, mounting faces and hole-pattern requirements.
Milling Coverage from Small Housings to Large Structural Parts
Our milling coverage extends from small connectors to large structural parts, with lengths up to approximately 2600 mm depending on setup. Cavities, mounting faces, hole patterns, threads and edge deburring on housings can be coordinated under the same drawing.
Machines Matched to Accuracy, Quality and Cost
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. High-precision mounting faces and hole patterns can be assigned separately from general cavities and external geometry, balancing machining quality and cost.
Material Certificates, Geometric Inspection and First-Article Reports
Material certificates, critical-dimension inspection and first-article reports can be supplied according to the order. Geometric tolerances such as flatness and hole-pattern position can be measured by CMM. Report formats follow customer requirements, with inspection scope agreed in the order.
Sample Approval before Batch Production
Orders start at 1 piece. Prototypes usually take 3-7 days and typical lead time is 10-15 days, depending on part complexity and quantity. Batch production can follow sample approval, and an NDA can be signed as needed.
FAQ
Which magnesium alloy and stock condition should I specify for a milled housing?
Specify the grade, procurement standard, blank form and supply condition. AZ31B is commonly wrought material such as plate or profiles, while AZ91D is commonly a casting grade. Different blank forms have different machining allowances and distortion risks. Material certificates can be supplied according to the order to verify the actual grade.
How do pocket depth and internal corners affect a magnesium milling quote?
Deeper cavities and smaller internal radii require longer, thinner tools and increase toolpath and inspection planning, making them major quotation factors. Increasing the internal radius of the same cavity from R1 to R3 usually allows a larger tool and saves machining time. Identify depth, minimum internal radius, ribs and thin-wall span for quotation.
How are mounting faces and hole patterns checked on a milled enclosure?
Geometric tolerances such as flatness and hole-pattern position can be measured by CMM with drawing-defined datums and inspection scope. Hole patterns also need the locating face and reference hole identified. Critical-dimension inspection and first-article reports can follow the order and customer report format.
How should corrosion protection be specified for a milled magnesium part?
Magnesium alloys generally need corrosion protection, with the method depending on grade, operating environment and appearance requirements. Coatings change mating-surface and thread dimensions. Identify mounting faces, grounding faces and threaded holes requiring masking, and state whether dimensional acceptance applies before or after treatment. The treatment route is established with the project during quotation.
How is magnesium chip and dust safety assessed during milling?
Fine magnesium chips and dust are flammable. Fine chips generated by thin-wall finish milling and small-tool machining of deep cavities and ribs require particular attention. Safety requirements are established for the grade, geometry and machining conditions within the project. State wall thickness, cavity depth and machining allowance during inquiry.
What files do you need to quote a magnesium milled part?
Provide 2D/3D drawings, material grade and condition, quantity, critical tolerances, surface treatment and application requirements. STEP, IGES, STP, DWG or dimensioned PDF files are accepted. The 3D model defines geometry, while mating tolerances and datums follow dimensioned drawings.
What tolerance applies to a large magnesium milled housing?
Dimensional tolerance for large parts over 500 mm is +/-0.05 mm. +/-0.003 mm applies to precision features and critical dimensions on small precision parts under 100 mm. Flatness of 0.02 mm applies to machining areas up to 1030 x 1030 mm. Larger areas or thin walls require structural and fixturing 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.
