Custom CNC Milling Services
Precision CNC milling services for custom metal and plastic parts, supporting rapid prototyping, low-volume production, and high-volume manufacturing with automated engineering support and global DDP delivery.
- ISO 9001
- NDA Available
- DFM Support
- Worldwide Shipping
Get a Fast CNC Milling Quote
Send your contact details, project notes, and CAD drawings. Our CNC engineering team will review tolerances, material, quantity, and quote next steps.
CNC Milling Capabilities at a Glance
LOM METAL MACHINING runs 100+ CNC milling centers for 3-axis, 4-axis, and 5-axis parts. Typical CNC milling tolerance is ±0.05 mm; qualified critical features can reach ±0.005 mm after DFM review, stable fixturing, and CMM inspection planning.
Discuss Your Milling Part| Item | Specification | Evidence |
|---|---|---|
| Machines | 100+ CNC milling centers; 3-axis, 4-axis, and 5-axis machining. | Machine chosen by part size, datum, tool access, and tolerance risk. |
| Part Size | Up to 1500 × 800 × 600 mm, subject to machine and fixture review. | Confirmed by travel, clearance, workholding, and inspection access. |
| Tolerance | Typical ±0.05 mm; critical features down to ±0.005 mm after review. | CMM inspection plan and dimensional report available. |
| Materials | 6061-T6, 7075-T6, 304, 316L, 17-4 PH, Ti-6Al-4V, brass, copper, PEEK, POM. | MTRs, lot traceability, and XRF verification when required. |
| Surface Finish | As-machined Ra 1.6-3.2 μm typical; fine milling down to Ra 0.8 μm. | Finish depends on material, tool path, cutter condition, and feature access. |
| Finishing | Bead blasting, anodizing, passivation, powder coating, and black oxide. | In-house anodizing and copper blackening reduce outsourcing delay. |
| Lead Time | Simple prototypes from 3 business days; typical orders 7-15 business days. | Confirmed after material, CAM, finishing, and inspection review. |
| Quality | ISO 9001:2015, IATF 16949:2016, ISO 13485, ISO 14001:2015. | IQC → IPQC → FQC → OQC; PPAP Level 3 support on request. |
Final tolerance, roughness, and delivery time are confirmed from the drawing, material, quantity, finishing process, and inspection scope.
Materials Built For
Milled Performance
Compare production-ready metals and engineering plastics for 3-axis, 4-axis, and 5-axis CNC milling, including 6061-T6, 7075-T6, 316L, C110 copper, Ti-6Al-4V, POM, PTFE, and PEEK.
Aluminum CNC Milling
6061-T6 and 7075-T6 aluminum are used for lightweight brackets, heat-sink housings, optical frames, drone parts, and aerospace-grade structural components. They support high-speed milling, stable anodized finishes, and tight tolerances down to ±0.005 mm when the geometry allows.
Stainless Steel CNC Milling
304 and medical-grade 316L stainless steel are selected for corrosion-resistant valve bodies, surgical fixtures, food-equipment parts, sensor housings, and precision plates. LOM controls tool heat, burr formation, and passivation requirements for low-volume builds through repeat production.
Brass CNC Milling
C360 brass is a high-machinability alloy for electrical connectors, valve cores, threaded inserts, precision fittings, and RF components. It offers low cutting resistance, stable dimensions, fine machined surfaces, and efficient lead times for detailed milled features.
Copper CNC Milling
C110 copper and CuCrZr are specified for conductive busbars, thermal blocks, EDM electrodes, 5G heat sinks, and battery-system components. Because copper conducts heat rapidly and can adhere to cutting tools, LOM optimizes tool geometry, coolant strategy, and flatness control.
Titanium CNC Milling
Ti-6Al-4V Grade 5 titanium is used for medical implants, surgical instruments, aerospace brackets, lightweight robotics parts, and high-strength fixtures. We apply rigid low-speed milling, sharp tooling, controlled coolant, and inspection traceability for surface integrity and dimensional stability.
Plastic CNC Milling
POM, PEEK, PTFE, Nylon, PC, and Ultem PEI are machined for insulation, wear resistance, lightweight fixtures, medical prototypes, and complex cavities. Temperature control and sharp tools help reduce deformation in thin walls, flat plates, and precision locating features.
Match Material, Tolerance, Finish, And Cost Before Production
Review more CNC machining materials or download our materials PDF for alloy options, plastic grades, finishing compatibility, inspection notes, and DFM recommendations from LOM engineering.
Typical CNC Milled Parts
12 typical CNC milled components covering 3-axis, 4-axis, 5-axis milling, ±0.005 mm tolerance capability, and materials including aluminum, stainless steel, titanium, copper, PEEK, and POM.
Housing
6061-T6 aluminum enclosure with threaded holes and sealing grooves.
Bracket
Lightweight 7075-T6 bracket with pockets and datum control.
Heat Sink
Thin-fin aluminum heat sink with flat thermal contact surfaces.
Base Plate
Flatness-controlled plate with dowel holes and counterbores.
Fixture
Inspection fixture with repeatable locating pins and nests.
Impeller
5-axis blade machining with smooth flow channels.
Medical Part
ISO 13485 controlled part with clean deburring and MTR traceability.
Robot Arm
Robotic link with bearing bores and lightweight pockets.
Sensor Body
IATF 16949 automotive body with precision mounting faces.
Copper Busbar
Copper component with controlled contact faces and deburred edges.
Optical Mount
Lens mount with tight bores and black anodized finish.
PEEK Insulator
Engineering plastic part for high-stability insulation applications.
Need DFM Feedback Before Quoting?
Send drawings, STEP files, material requirements, and target quantity. LOM engineers review tolerances, machining type, surface finish, and inspection requirements for a 4-hour engineering quote.
Surface Finishing Options for Milled Parts
In-house anodizing and copper blackening plus 20+ controlled finishes for aluminum, stainless steel, titanium, copper, brass, and engineering plastics.
As-Machined
Direct CNC output for datum features, prototypes, and internal fixtures with no secondary coating.
- Ra Roughness
- Ra 1.6-3.2 μm
- Materials
- 6061-T6, 7075-T6, 304/316L, brass, copper, PEEK.
- Appearance
- Natural metal, visible tool paths.
- Best Use
- Tolerance-critical surfaces and DFM validation.
Bead Blasting
Controlled abrasive media reduces milling marks before anodizing or cosmetic inspection.
- Ra Roughness
- Ra 1.2-2.8 μm
- Controls
- Media size, pressure, masking, cosmetic direction.
- Appearance
- Matte, low reflection, uniform texture.
- Best Use
- Optical brackets, aluminum enclosures, camera components.
Type II Anodizing
Sulfuric anodizing for corrosion resistance and repeatable color on machined aluminum.
- Thickness
- 5-25 μm
- Materials
- 6061-T6, 7075-T6, 2024, 5052.
- Colors
- Clear, black, red, blue, gold, custom dye.
- Best Use
- Camera lens parts, 5G covers, electronics housings.
Type III Hardcoat
Dense oxide layer for wear resistance, dielectric performance, and high-duty aluminum parts.
- Thickness
- 25-75 μm
- Ra Roughness
- Ra 2.0-4.0 μm
- Materials
- 7075-T6, 6061-T6, hard aluminum alloys.
- DFM Note
- Mask threads, bores, sliding fits, and ground points.
Chem Film
Chromate conversion coating preserves electrical conductivity while adding corrosion protection.
- Standard
- MIL-DTL-5541
- Coating Class
- Class 1A / Class 3 as specified.
- Materials
- 6061-T6, 7075-T6, 5052 aluminum.
- Best Use
- EMI housings, grounding faces, aerospace brackets.
Passivation
Removes free iron and improves the chromium-rich protective layer after machining.
- Standards
- ASTM A967 / AMS 2700
- Ra Roughness
- Ra 0.8-1.6 μm
- Materials
- 304, 316L, 17-4 PH stainless steel.
- Best Use
- Medical devices, sensors, fluid-contact components.
Electropolishing
Electrochemical smoothing reduces burr peaks and improves cleanability.
- Ra Roughness
- Ra 0.2-0.8 μm
- Materials
- 316L, 304, 17-4 PH, selected nickel alloys.
- Appearance
- Bright, smooth, low-particle surface.
- Quality
- ISO 13485 workflow and material traceability available.
Black Oxide
Thin black conversion layer for steel parts requiring minimal dimensional change.
- Thickness
- 1-2 μm
- Materials
- Carbon steel, alloy steel, tool steel.
- Appearance
- Black, low-glare, oil-sealed surface.
- Best Use
- Fixtures, shafts, tooling, optical hardware.
Zinc Plating
Electroplated zinc protects machined steel brackets, housings, and hardware.
- Thickness
- 5-25 μm
- Finish
- Clear, blue-white, yellow, black passivate.
- Materials
- Carbon steel, alloy steel, fasteners.
- Best Use
- Automotive brackets, fixtures, mounting hardware.
Nickel Plating
Nickel coating adds hardness, corrosion resistance, and stable contact surfaces.
- Thickness
- 3-25 μm
- Options
- Electrolytic nickel or electroless nickel by spec.
- Materials
- Steel, copper, brass, aluminum with pretreatment.
- Best Use
- Electrical contacts, wear faces, precision hardware.
Brushing
Mechanical brushing creates a directional grain for visible panels and consumer-facing parts.
- Abrasive Range
- #180-400 grit
- Ra Roughness
- Ra 0.8-2.5 μm
- Materials
- Aluminum, stainless steel, brass.
- Best Use
- Faceplates, enclosures, panels, optical housings.
Polishing
Mechanical polishing reduces surface peaks for smooth cosmetic or functional areas.
- Ra Roughness
- Ra 0.1-0.4 μm
- Finish Level
- Satin, bright, mirror by drawing spec.
- Materials
- Stainless steel, aluminum, brass, titanium.
- Best Use
- Medical parts, optical interfaces, cosmetic covers.
Powder Coating
Durable polymer coating for color, corrosion protection, and handling resistance.
- Thickness
- 60-120 μm
- Ra Roughness
- Ra 2.5-6.3 μm
- Appearance
- Matte, satin, gloss, textured, custom RAL colors.
- DFM Note
- Mask threads, bores, contacts, and grounding points.
PTFE Coating
Fluoropolymer coating reduces friction and improves chemical resistance on selected machined parts.
- Thickness
- 15-40 μm
- Property
- Low friction, non-stick, chemical resistant.
- Materials
- Aluminum, stainless steel, steel with pretreatment.
- Best Use
- Sliding interfaces, jigs, medical tooling, automation parts.
Copper Blackening
Deep black conductive finish for copper heat sinks, shielding parts, and electronic hardware.
- Ra Roughness
- Ra 0.8-2.0 μm
- Property
- Conductive black surface, controlled batch color.
- Materials
- Copper C110, brass, selected copper alloys.
- Best Use
- 5G thermal modules, grounding parts, optical assemblies.
Laser Marking
Permanent part identification for serial numbers, QR codes, UID marks, and lot traceability.
- Mark Types
- Text / QR / UID / Logo
- Materials
- Aluminum, stainless steel, titanium, plastics.
- Quality
- Supports IQC → IPQC → FQC → OQC traceability.
- Best Use
- Medical, automotive, aerospace, and electronics parts.
Need coating thickness, cosmetic criteria, or finishing cost?
Share material grade, masking zones, target Ra, color, thickness, quantity, and inspection documentation needs. LOM reviews 20+ finish options for milled aluminum, stainless steel, titanium, copper, brass, and engineering plastic parts.
NDA available · No MOQ restrictions · PPAP Level 3 support on request
CNC Milling Tolerance and Design Guide
Use these values as early DFM references for 3-axis, 4-axis, and 5-axis CNC milling. LOM can hold localized tolerances down to ±0.005 mm when material, geometry, clamping, and inspection access allow.
| Feature / Requirement | Typical CNC Milling Range | Precision Capability | Design Note |
|---|---|---|---|
| Standard Tolerance | ±0.05 mm to ±0.10 mm for general machined dimensions | ISO 2768-mK or customer drawing standard supported | Use standard tolerance for non-critical dimensions to reduce machining time and inspection cost. |
| Tight Tolerance | ±0.01 mm for selected functional features | Down to ±0.005 mm when geometry, material, datum access, and clamping allow | Apply tight tolerance only to bearing fits, optical seats, sealing faces, datum features, and assembly-critical dimensions. |
| Wall Thickness | Aluminum: ≥0.8-1.0 mm; stainless steel / titanium: ≥1.0-1.5 mm; plastics: ≥1.5-2.0 mm | Thin-wall machining available with controlled toolpath, reduced cutting force, and staged clamping | Avoid long unsupported walls. Add ribs, increase corner radius, or allow stress-relief operations for large thin plates. |
| Hole Size | Drilled holes from Ø0.5 mm; precision bored / reamed holes commonly Ø2 mm and above | ±0.02 mm to ±0.05 mm as-machined; H7 fits available by reaming or boring | Specify fit class clearly: H7, slip fit, press fit, dowel pin, bearing seat, or threaded hole. |
| Hole Depth | Recommended depth ≤5×D for standard drilling; deep holes up to 10×D require review | Deep-hole accuracy depends on diameter, material, coolant access, and drill wander control | For blind holes, define usable depth separately from drill tip depth. Add through-holes where possible for chip evacuation. |
| Corner Radius | Minimum internal radius typically R0.5 mm; preferred radius R1.0-R3.0 mm | Smaller radii possible by micro end mills or EDM, subject to depth and material | Set internal corner radius at least 130% of tool radius where possible to reduce chatter and improve surface finish. |
| Thread | Metric threads from M1.6; UNC / UNF / NPT supported on request | Thread milling, tapping, and thread gauges available for inspection | Recommended full thread engagement: 1×D to 1.5×D for metals, 2×D or inserts for plastics and soft materials. |
| Open and closed pockets, stepped pockets, O-ring grooves, and light-weighting cavities | Flat bottom, profile, and wall tolerance can be CMM verified for critical pockets | Use generous corner radii and avoid extremely narrow slots. Design pockets with tool access from one or more sides. | |
| Pocket Depth | Recommended depth ≤4× tool diameter for stable milling; deeper cavities require DFM review | High-aspect-ratio pockets possible with reduced feed, extended tooling, and intermediate inspection | Deeper pockets increase tool deflection and corner radius. Add relief areas or split the part if precision walls are required. |
| Undercut | T-slot, dovetail, back-face relief, O-ring undercut, and custom form undercuts | Machined by T-slot cutters, lollipop tools, angle heads, 5-axis access, or EDM when needed | Provide undercut width, depth, corner radius, tool clearance, and inspection datum on the drawing. |
| Maximum Part Size | Common milling envelope up to 1,000 × 600 × 500 mm; larger parts reviewed by machine availability | 3-axis, 4-axis, and 5-axis machining strategy selected based on geometry and datum control | For large aluminum plates, frames, or housings, include flatness, parallelism, stress-relief, and packaging requirements. |
| Surface Roughness | Ra 1.6-3.2 μm common for milled surfaces | Ra 0.8 μm or Ra 0.4 μm target available with finishing passes and process control | Call out Ra only where sealing, optical seating, friction, cosmetic, or fatigue performance requires it. |
Upload your CAD files for a CNC milling quote
Send STEP, IGES, X_T, STL, DWG, PDF, or 2D drawings. LOM engineers will review tolerance feasibility, wall thickness, hole depth, internal radius, pocket depth, material selection, and surface finishing requirements before quoting.
CNC Engineering Support Before Production
LOM engineers review CAD files, material callouts, GD&T, tolerance targets, and machining routes before cutting metal, helping reduce quote risk and improve first-pass manufacturability.
Engineering Evidence
- 80+ DFM engineers support pre-quote manufacturability checks.
- ±0.005 mm precision capability with CMM inspection and traceability.
- 3-axis, 4-axis, 5-axis milling and Swiss-type turning from prototype to volume production.
DFM Check
We review STEP, IGES, DWG, and PDF files for thin walls, deep pockets, sharp internal corners, undercuts, and tool-access limits.
Material & Tolerance
We match materials and GD&T to real machining controls, including 6061-T6, 7075-T6, 316L, 17-4 PH, Ti-6Al-4V, PEEK, POM, and Ultem.
Control Point
Reserve ±0.005 mm tolerance for critical features and relax non-critical dimensions where function allows.
Process Planning
We plan cutter access, workholding, surface finish, inspection points, and scalable routing for 1-piece prototypes through 1,000,000+ production parts.
Talk to LOM Engineers
Need help confirming tolerances, materials, or machining feasibility?
Send your CAD files and requirements. Our engineering team can review manufacturability, suggest cost-saving options, and explain the best CNC process for your part.
Quality Control for Precision CNC Milling
Claim: LOM METAL MACHINING is built for regulated precision milling programs. Evidence: ISO 9001:2015, IATF 16949:2016, ISO 13485, ISO 14001:2015, 20+ inspection tools, CMM inspection, XRF material verification, and PPAP Level 3 support.
Request Inspection PlanCertifications
ISO 9001:2015, IATF 16949:2016, ISO 13485, ISO 14001:2015.
Inspection Equipment
CMM, height gauges, micrometers, calipers, pin gauges, thread gauges, roughness testers, and visual inspection systems.
Material Verification
XRF analyzer, supplier MTR review, batch identification, and raw material lot traceability.
Reports
FAI, dimensional inspection, COC, material reports, surface finish records, and PPAP documentation.
Nine Quality Inspection Stations
Each station supports LOM METAL MACHINING's IQC → IPQC → FQC → OQC workflow, connecting measurable inspection data with ISO 9001:2015, IATF 16949:2016, ISO 13485, and PPAP Level 3 documentation requirements.
CMM Dimensional Inspection
Coordinate measuring machines verify GD&T features, true position, flatness, perpendicularity, and critical dimensions for CNC milled parts with tolerance targets down to ±0.005 mm.
XRF Material Verification
XRF alloy checks confirm incoming 6061-T6, 7075-T6, 316L, 17-4 PH, brass, copper, and Ti-6Al-4V batches against supplier MTRs before production release.
Surface Roughness Testing
Profilometer inspection validates machined and finished surfaces, including bead blasting, anodizing, passivation, and high-precision features requiring roughness targets down to Ra 0.4 μm.
Optical Visual Inspection
Magnified visual systems check burrs, edge breaks, chamfer consistency, coating coverage, and cosmetic defects on optical housings, medical components, and electronics fixtures.
Thread and Pin Gauge Checks
Go/no-go thread gauges, plug gauges, and pin gauges verify tapped holes, precision bores, mating shafts, and Swiss-turned features across Ø0.5 mm to Ø32 mm production ranges.
Height Gauge Datum Inspection
Digital height gauges on granite plates verify datum-controlled dimensions, step heights, perpendicularity, and milling depth features during first-piece approval and final inspection.
IPQC In-Process Checks
Micrometers, calipers, bore gauges, and process control records monitor tool wear, thermal drift, and dimensional stability throughout CNC milling and Swiss turning runs.
FAI and PPAP Documentation
FAI reports, balloon drawings, dimensional results, material certificates, COC records, and PPAP Level 3 packages support automotive, medical, aerospace, and regulated supply chains.
Final OQC and Traceability
Outgoing quality control confirms inspection status, batch labels, protective packaging, COC documentation, and full IQC → IPQC → FQC → OQC traceability before international shipment.
How Our CNC Milling Service Works
-
01
Upload Files
Send STEP, IGES, X_T, STL, DWG, PDF, quantity, material, finish, and inspection requirements.
-
02
DFM Review
Engineers evaluate tool access, tolerance feasibility, radii, threads, wall thickness, and cost-saving changes.
-
03
Quote
Receive process plan, lead time, unit price, finishing plan, and inspection documentation scope.
-
04
Production
CNC programming, fixture setup, machining, in-process checks, finishing, and final inspection.
-
05
Delivery
Packaging, documentation, export logistics, customs support, and shipment tracking.
Need a CNC Milling Quote With Tolerance Feasibility Reviewed?
Send your 3D CAD files, 2D drawings, material grade, annual volume, surface finish target, and critical dimensions. Our engineering team can review 3-axis, 4-axis, and 5-axis milling feasibility, including ±0.005 mm tolerance requirements, fixture strategy, tool access, Ra targets, and inspection documentation scope.
CNC Machined Product Collection
Representative precision parts manufactured by LOM METAL MACHINING using 3-axis, 4-axis, 5-axis milling, Swiss-type turning, EDM, in-house anodizing, passivation, and CMM-verified inspection workflows.
What CNC Milling Buyers Say About LOM
LOM helped us move from prototype housings to production parts without changing suppliers. Their DFM feedback reduced unnecessary tight tolerances before we released the drawing.
The inspection reports were clear enough for our supplier quality file. We needed 316L parts with passivation and traceability, and LOM delivered consistent documentation.
Their 5-axis capability gave us cleaner datum control and fewer setup-related deviations on a difficult titanium bracket.
Why Choose Us for CNC Milling?
Scale Agility
From 1-piece CNC prototypes to 1,000,000+ volume production with no MOQ restrictions.
Engineering First
80+ engineers review manufacturability, tolerance risk, fixture strategy, and cost reduction opportunities.
Supply Chain Control
In-house finishing, inspection, export support, and logistics experience reduce delays and handoff risk.
Quality Assurance
ISO 9001, IATF 16949, ISO 13485, CMM, XRF, PPAP, and full IQC → IPQC → FQC → OQC traceability.
What Is CNC Milling?
What Is CNC Milling
CNC milling is a subtractive manufacturing process where rotating cutting tools remove material from a solid block.
How CNC Milling Works
The process starts with CAD/CAM programming, toolpath simulation, fixture setup, machining, measurement, deburring, finishing, and inspection.
Other Benefits
CNC milling enables fast design iteration, material flexibility, tight tolerance control, functional prototypes, and scalable manufacturing.
CNC Milling Service FAQs
What tolerances can you hold for CNC milled parts?
General machining tolerances are often ±0.05 mm to ±0.10 mm. For critical features, LOM can achieve tight tolerances down to ±0.005 mm when geometry allows.
Do you provide 5-axis CNC milling?
Yes. We provide indexed and simultaneous 5-axis CNC milling for complex contours, angled faces, aerospace brackets, and medical components.
Which file formats can I send for quotation?
Preferred formats include STEP, IGES, X_T, SLDPRT, and PDF drawings. DWG, DXF, STL, and sample photos can also help.
Can you provide inspection reports?
Yes. Available reports include first article inspection, dimensional inspection, CMM reports, material certificates, COC, surface finish records, and PPAP documentation.
Request a CNC Milling Quote
Upload your part files and our engineers will review material, process, tolerance, finishing, and inspection requirements. Typical quote response: 4 business hours for complete RFQs.
Email: sales@lommetal.com
Support: CNC milling DFM, material selection, finishing, inspection plans, and logistics.
Location: Greater Bay Area, China · Global shipping support.