Custom Online CNC Machining Services
CNC machining cuts solid metal or plastic blocks into finished parts using rotating tools. Holds ±0.01mm （Full Tolerance Standard）on critical features and ISO 2768-m as standard elsewhere, runs from 1 prototype to 10,000+ production parts on the same machine. The default process for functional parts in aluminum, stainless, brass, POM, and any other material where tolerance and strength matter. For design best practices, see our CNC DFM Guidelines
CNC Machining Capabilities
| Feature | Description |
| Maximum Part Size | CNC Milling: 4000×1500×600mm／ CNC Turning: Ø200×500mm |
| General Tolerances | Metals: ISO 2768-m (±0.05–0.5mm), ISO 2768-f on request Plastics: ISO 2768-c standard |
| Precision Tolerances | Down to ±0.01mm on critical features |
| Standard Lead Time | 5 business days (simple parts 1–3 days) |
| Machines | 3-, 4- & 5-axis CNC Milling, CNC Turning, EDM, Swiss Machining |
| Post-Processing | Surface Finishing |
| Type | Material | Service | Process | More Info |
|---|---|---|---|---|
| ABS | ABS | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| PC | PC | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| PC-ABS | PC-ABS | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| PMMA / Acrylic | PMMA | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| POM / Acetal | POM (Delrin) | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Nylon / PA | PA6 | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Nylon / PA | PA66 | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Glass-Filled Nylon / PA | PA6-GF30 | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Glass-Filled PBT | PBT-GF30 | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| PTFE / Teflon | Teflon | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| PEEK | PEEK | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Glass-Filled PEEK | PEEK-GF30 | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Bakelite / Phenolic | Bakelite | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Type | Material | Service | Process | More Info |
|---|---|---|---|---|
| Aluminum | 2024 | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Aluminum | 5052 | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Aluminum | 5083 | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Aluminum | 6061-T6 | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Aluminum | 6063 | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Aluminum | 7075-T6 | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Aluminum | ADC12 | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Magnesium | AZ31B | CNC Machining | CNC Milling | Data Sheet |
| Magnesium | AZ91D | CNC Machining | CNC Milling | Data Sheet |
| Stainless Steel | SUS304 | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Stainless Steel | SUS316 | CNC Machining | CNC Milling | Data Sheet | Selection Logic |
| Carbon Steel | 45# / AISI 1045 | CNC Machining | CNC Milling | Data Sheet |
| Carbon Steel | Q235 / ASTM A36 | CNC Machining | CNC Milling | Data Sheet |
| Alloy Steel | 40Cr / AISI 4140 | CNC Machining | CNC Milling | Data Sheet |
| Brass | H62 / C360 | CNC Machining | CNC Milling | Data Sheet |
| Copper | T2 / C110 | CNC Machining | CNC Milling | Data Sheet |
| Type | Material | Service | Process | More Info |
|---|---|---|---|---|
| Foam | Foam | CNC Machining | CNC Milling | Data Sheet |
(Coming Soon)
Materials Supported
Common Metal Materials
Aluminum machines fast and cleanly, cutting speeds 3–5× faster than steel, longer tool life on cheap inserts. 6061 is the default for brackets, housings, and structural parts. 6082 is the European equivalent with similar properties. 7075 runs harder and stronger but costs 3× more; reserved for aerospace structural parts and components under sustained load. 2024 for parts that need fatigue resistance. All aluminum grades anodize, with 6061 and 6063 taking color most evenly.
Stainless steel machines slower than aluminum but holds tighter tolerances on small features. 304 is the general-purpose grade, food contact, light corrosion, decorative parts. 316 adds molybdenum for saltwater and chemical environments. 303 has added sulfur for easier machining but lower corrosion resistance, used on free-cutting turned parts. 17-4 PH for parts that need high strength and corrosion resistance after heat treatment.
Carbon steel is the cheapest option and the strongest at the same hardness range. 1018 mild steel for structural brackets and weldments. 1045 medium-carbon for shafts, gears, and parts needing some hardness. 4140 alloy steel for high-strength structural parts, often heat-treated to HRC 28–32 after machining. All carbon steel grades rust without surface protection, zinc plating, black oxide, or powder coat after machining
Brass machines faster than any other common metal and produces clean chip evacuation. C360 free-cutting brass is the standard grade for fittings, valves, and threaded components. C260 cartridge brass for parts needing more cold-working before final machining. Brass holds a polished finish on its own without coating, common on decorative hardware and electrical connectors.
Copper machines softer than brass and tends to drag on the cutter, sharp tools and high feed rates work better than slow careful cuts. C110 pure copper for electrical bus bars, grounding straps, and heat sinks. C145 tellurium copper machines better but loses some conductivity. C932 bearing bronze for bushings and wear surfaces. Copper parts often require chemical passivation or tin plating to prevent surface oxidation.
Common Plastic Materials
POM holds dimensions during and after machining better than any other engineering plastic, minimal stress relief needed. Low coefficient of friction makes it the go-to for gears, bushings, and sliding parts. Drills clean, taps clean threads. Black POM resists UV slightly better than natural white. Avoid POM on parts that see acids or strong oxidizers.
Nylon machines tougher than POM but absorbs moisture, parts grow 0.5–1% in humid conditions, which shifts dimensions on tight-tolerance features. Condition stock material before final passes, or hold critical dimensions with post-conditioning machining. MC901 cast nylon machines more stably than extruded nylon. Used for wear pads, structural pulleys, and impact-resistant brackets.
ABS is softer than POM or nylon, easier to scratch and dent during fixturing. Machine with sharp tools, light cuts, and air blast for chip clearance (no flood coolant; coolant absorbs into the surface). Used for prototype housings and parts that will be glued, vapor-smoothed, or painted. Not for load-bearing applications or parts running at temperatures above 80°C.
PC is harder to machine than ABS, cracks easily at sharp internal corners and shows stress lines along tool paths. Slow feed rates, sharp single-flute cutters, and minimal heat buildup. Don’t use chlorinated coolants; PC stress-cracks on contact. Common for clear prototype lenses, structural panels, and impact-resistant covers.
Material Selection Guidance
Material choice on CNC parts usually comes down to one question: what does the part have to survive in service? Aluminum 6061 covers 60% of jobs, strong enough, light, cheap, anodizes well. Stainless steel 304 for corrosive environments or food contact. Brass and copper for electrical or fluid applications. POM for plastic wear parts; PC and ABS for cosmetic prototypes.
Material affects machining cost more than most designers expect. A part in 7075 aluminum costs 2× the same part in 6061. A part in stainless 316 costs 3–4× the same part in 304. PEEK plastic costs 10× POM. Worth it only when the application actually demands the upgrade, otherwise it’s money cut into chips.
Tolerances & Precision
Tight tolerances drive CNC cost faster than any other factor. ±0.2mm is standard on most features. ±0.05mm requires a slower second pass and post-machining inspection. ±0.01mm requires controlled machining and full dimensional inspection. Anything tighter than ±0.005mm moves to grinding or hand finishing. Call out tight tolerances only on features that actually need them, mating bores, bearing fits, threaded holes. Everything else stays at general machining tolerance.
| General Tolerances | Metals: ISO 2768-m. ±0.1mm up to 6mm, ±0.2mm from 6 to 30mm, ±0.3mm from 30 to 120mm, ±0.5mm from 120 to 400mm. ISO 2768-f available on request. Plastics: ISO 2768-c. ±0.2mm up to 3mm, ±0.3mm from 3 to 6mm, ±0.5mm from 6 to 30mm, ±0.8mm from 30 to 120mm. |
| Precision Tolerances | Tolerances down to ±0.01mm with controlled machining and post-process inspection. Tighter than ±0.005mm requires grinding or hand finishing |
| Min Wall Thickness | Metals: 0.5mm Plastics: 1.0mm. Thinner walls deflect under cutting force. |
| Min End Mill Size | 0.5mm. Smaller cutters break under standard feed rates |
| Min Drill Size | 1mm standard. 0.3mm achievable on dedicated micro-drilling setups at higher cost. |
| Maximum Part Size | CNC Milling: 4000×1500×600mm CNC Turning: Ø200×500mm |
| Minimum Part Size | CNC Milling: 5×5×5mm CNC Turning: Ø2×2mm |
| Production Volume | Prototyping: 1–100 pcs Low volume: 101–10,000 pcs High volume: 10,000+ pcs |
| Lead Time | 5 business days for most projects. Simple parts ship in 1–3 days |
Surface Finishing Options
As Machined
Standard CNC finish with surface roughness Ra 1.6–3.2μm typical, up to Ra 6.3μm on deep pockets and long-reach features. Visible tool marks on flat surfaces and faint helical lines on bored holes. Sharp edges are broken to 0.3–0.5mm.
Bead Blasting
Glass beads or aluminum oxide media blasted onto the surface under pressure. Removes tool marks and creates a uniform matte texture. Standard pre-anodizing treatment for aluminum parts, since bead-blasted surfaces hold anodize color more evenly than as-machined finishes.
Brushing
Abrasive belt drawn across the surface in one direction, producing a linear grain pattern at Ra 0.4–0.8μm. Commonly applied to stainless steel panels, aluminum trim, and decorative parts. Grit 120–240 produces the standard #4 architectural finish used in most builds.
Anodizing
Electrochemical process for aluminum only. Type II builds a 5–25μm color layer for decoration and basic corrosion protection, available in black, clear, red, blue, and gold. Type III hard anodize builds a 25–75μm wear-resistant layer in gray or black. Mask threads and bearing surfaces.
Design Guidelines
A part can be drawable in CAD and still take 4 hours per piece to machine. Good CNC design means tools can reach all features in 1–2 setups, walls are thick enough to hold under cutting force, and internal corners match standard tool diameters. Cuts cycle time more than picking a cheaper material does
| Core DFM Principles | Better DFM for CNC machining usually means: – practical wall thickness – reasonable hole size and hole depth – internal corner radii that match cutting-tool reality – controlled cavity depth – realistic thread depth – tight tolerances only where function requires them |
| Wall Thickness | The document uses these practical starting points: – Metals: around 0.8 mm – Plastics: around 1.5 mm – For some turned features, 0.5 mm / 0.020 in is treated as a lower threshold in many cases. |
| Holes and Hole Depth | Small holes and deep holes are common machining cost drivers. The design guidance recommends keeping holes as large as function allows and keeping drill-based hole depth around 4× diameter when possible, while noting that deeper drilling up to 12× diameter may be possible in more aggressive cases but becomes more process-sensitive. Blind holes should also include extra depth to account for drill tip shape and tool clearance. |
| Internal Corners and Tool Radius | CNC milling cutters are round, perfectly sharp internal corners aren’t possible. Standard practice: internal corner radius of 1.5–3mm matches common end mill sizes (Ø3, Ø6 cutters). Forcing a 0.5mm radius means switching to a smaller cutter, which slows the job and costs more. If a mating square feature needs clearance, add a relief slot or dog-bone cut at the corner instead of forcing a sharp internal corner. |
| Threads | The guidance emphasizes that threads are easy to over-design. Standard thread sizes should be used where possible, and thread engagement of roughly 1×D to 2×D is often enough for many applications. Deeper threads usually add tapping difficulty and cycle time without delivering useful additional strength. |
| Deep Cavities and Long-Reach Features | Deep cavities are among the most common DFM problems. The recommendation is to keep cavity or pocket depth within about 4× tool width where possible, because long-reach tools reduce stiffness and increase chatter, deflection, and surface-finish problems. |
| Avoid Unnecessary Precision | Specifying ±0.025mm on a cosmetic face that only needs to look flat doubles inspection time and triples scrap risk. Mark critical dimensions on the drawing with tight tolerances; leave the rest at general machining tolerance. A good drawing tells the machinist which faces are functional and which are decorative. |
Typical Applications
Concept Models
Early visual and tactile models that lock in form, proportion, and styling before any tooling is committed.
Functional Prototypes
Working parts in production-intent materials, built to verify fit, function, and mechanical performance under real loads.
Engineering Validation
Rigorous testing of strength, durability, and environmental resistance to confirm the design meets performance and safety targets.
Fit & assembly testing
Dimensional and mating checks across components to verify tolerances, clearances, and assembly before scale-up.
Market testing samples
Near-final, cosmetically finished units in small batches for customer, retailer, and certification feedback.
Bridge production
Limited pre-mass runs on near-final tooling that keep you shipping while hard tooling and full production ramp up.
Equipment & Capacity
Picking 3-axis vs 5-axis vs Swiss machining usually comes down to two questions: how many sides of the part need machining, and how small are the features. 3-axis handles 80% of jobs. 5-axis adds value when part geometry needs more than 2 setups to reach. Swiss for slender turned parts under Ø32mm.
Quality Control Flow
Incoming inspection
Material certs checked against the PO before stock hits the cutter. Aluminum bars verified for grade (6061 vs 6082 look identical, machine differently). Stainless verified for grade and heat treatment condition. Bar stock checked for straightness, bent stock causes scrap during the first roughing pass.
In-process inspection
First-article check on the first 1–3 parts off each setup. Critical dimensions verified before running the full batch. Mid-run sampling at 25%, 50%, and 75% completion on batches over 100 pieces, catches tool wear drift before scrap rate climbs. Tool changes logged with serial numbers for traceability.
Final inspection
Dimensional check on every feature with a drawing tolerance. CMM measurement on tolerances tighter than ±0.05mm. Visual inspection for tool marks, burrs, scratches, and surface defects under controlled lighting. Threaded holes gauged with go/no-go pins. Reject parts pulled and logged with failure cause.
Documentation and traceability
Material certs, inspection reports, and CMM data archived per lot. Parts trace back to specific stock heat number, machinist, machine, and inspection record. PPAP, ISIR, and first-article documentation available on request for automotive, medical, and aerospace customers. ISO 9001:2015 certified quality system.
Related Solutions
Rapid Prototyping
Low Volume Production
Production Tooling
End-to-End Manufacturing
CNC Machining: Common Questions
What file formats do you accept for CNC machining orders?
STEP (.stp/.step) is preferred. IGES, PARASOLID (.x_t), and DXF (for 2D profiles) also work. PDF drawings are accepted alongside 3D files for GD&T callouts, thread specs, and surface finish requirements. If you only have a 2D drawing, send it and we will advise on the best path forward.
What is the standard tolerance for CNC machined parts?
Default tolerance follows ISO 2768-m: ±0.1mm on dimensions up to 6mm, ±0.2mm from 6 to 30mm, and ±0.3mm from 30 to 120mm. ISO 2768-f is available on request when the drawing calls for it. Critical features such as bores, shafts, and mating faces hold ±0.01mm. Specify your tolerance requirements in the drawing or RFQ and we confirm feasibility before production starts.
What is your minimum order quantity?
No minimum. One prototype runs on the same equipment as a 5,000-piece production batch. Pricing per part decreases with volume; if you are evaluating cost at different quantities, include that in the RFQ and we will quote multiple tiers.
How long does it take to get machined parts?
Prototypes in standard materials (6061 aluminum, 304 stainless, POM) ship in 3 to 5 business days from drawing approval. Complex 5-axis parts or tight-tolerance orders typically run 7 to 10 days. Production orders are quoted with lead time based on quantity and material availability. DHL/FedEx express delivery to North America and Europe is standard.
Which materials can you machine?
Metals: aluminum alloys (6061, 7075, 2024), stainless steel (303, 304, 316L, 17-4PH), titanium (Grade 5 / Ti-6Al-4V), brass (C360), copper, steel alloys (4140). Plastics: POM/Delrin, PEEK, PC, ABS, PMMA, PA6, PA66, Teflon/PTFE, UHMWPE. If your material is not listed, send the spec and we will confirm machinability.
Do you offer 5-axis CNC machining?
Yes. 5-axis simultaneous machining handles undercuts, compound angles, and complex contoured surfaces that 3-axis cannot reach in a single setup. This reduces setups, lowers the risk of fixturing error, and holds tighter positional tolerances on multi-face features. Request 5-axis capability in your RFQ if the part geometry requires it.
What surface finishes are available?
As-machined (Ra 1.6 to 3.2 μm), bead blast, anodizing (Type II clear or colored, Type III hard anodize), electropolishing, powder coating, nickel/chrome plating, black oxide, and custom paint. Surface finish callouts belong on the drawing; include Ra value or a specific standard if you have one.
Do you sign NDAs before reviewing design files?
Yes. Send an NDA request to [email protected] before uploading files. We return a signed copy within 24 hours on business days. Files can also be uploaded through our secure RFQ portal.
Can you supply inspection reports or CMM data?
Yes. First Article Inspection (FAI) reports and CMM dimensional reports are available on request. For medical, aerospace, or defense parts, specify the documentation requirements in the RFQ: AS9100, ISO 13485, material certs (mill certs / CoC), or PPAP are handled on a project basis.
I have a STEP file but no drawing. Can you still quote?
Yes, but a drawing helps. Without a drawing, we machine to the model and apply ISO 2768-m tolerances by default. Critical dimensions, thread specs, surface finish, and GD&T callouts must be on a drawing to be controlled. A marked-up PDF alongside the STEP file is enough.
Ready to Quote Your CNC Prototype?
Upload your STEP file and get a DFM review + quote within 12 hours. No tooling cost. Minimum 1 part.
Related Case Studies
Shear Modulus for Polymers and 3D-Printed Parts: Formula, Torsion Testing, Dynamic G, and Anisotropy
Ultimate Tensile Strength (UTS): What It Measures and How to Read It on an MTR
Bulk Modulus in Engineering Materials: Compressibility, Elastic Constants, Measurement Limits and Design Use
Tensile Stress in 3D-Printed Parts: Formula, Stress-Strain Data, Anisotropy, Test Methods and Design Limits
Modulus of Elasticity vs Strength: What Stiffness Means for CNC Part Design
