CNC Milling Services
3-axis and 5-axis milling of aluminum, steel, stainless, titanium, and plastics — prototype to production.
Precision Milled Parts, Made to Your Drawing
IsoCNC provides CNC milling services for custom prismatic parts — housings, brackets, plates, manifolds, fixtures, and enclosures — machined from your CAD model and inspected against your 2D drawing. CNC milled parts ship with their inspection reports. Milling happens on our own machining centers in our China factory: 3-axis work for plates and pockets, 4th-axis indexing for features around a cylinder, and 5-axis for compound geometry. From one-off prototypes to repeat production runs, finishing and export packing are handled in the same workflow, so one PO covers the part from raw stock to a finished, inspected, packed product.
What We Mill
- Housings and enclosures — pocketed aluminum and plastic enclosures with threaded holes, sealing grooves, o-ring glands, and cosmetic finishes
- Brackets and structural parts — 6061 and 7075 aluminum, 4140 steel, titanium Grade 5, with weight-saving pockets and ribbed profiles
- Manifolds and fluid components — drilled and reamed intersecting passages, NPT and metric ports, flat sealing faces
- Plates and fixtures — tooling plates, jigs, test fixtures, and base plates held to tight flatness
- Heat sinks and thermal parts — finned and pocketed aluminum and copper, including thin-fin profiles
Milling Capability Specifications
| Capability | Specification |
|---|---|
| Max part size | 40 × 24 × 20 in (1,000 × 600 × 500 mm) |
| General tolerance | ±0.005 in (±0.13 mm) |
| Precision features | ±0.001 in (±0.025 mm), quoted against drawing |
| Minimum wall thickness | 0.020 in (0.5 mm) typical, material-dependent |
| As-machined finish | Ra 3.2 µm (125 µin); to Ra 0.8 µm (32 µin) on request |
| Batch range | 1 pc prototype to 10,000+ pcs production |
| Typical lead time | Prototypes from 3 days; production typically 2–3 weeks |
3-Axis, 4-Axis, and 5-Axis Milling
Most milled parts run on 3-axis vertical machining centers; a 4th-axis indexer handles features around a cylinder or on multiple faces without a second fixture. For complex contours, deep pockets at compound angles, or parts where feature-to-feature accuracy across faces matters, we route the job to 5-axis — fewer setups, better geometry, and usually lower cost on complexity. The drawing decides the process: if a part can be finished on 3-axis with one re-clamp, we quote it that way. Workholding is planned at the same time — vises with soft jaws for most prismatic work, dedicated fixtures when batch size justifies them — because clamping strategy is what keeps thin-wall and flatness callouts honest. See 5-axis CNC machining.
Tolerances and Finishes
General milled features hold ±0.005 in (±0.13 mm) as standard. Critical dimensions, bore tolerances, and true-position callouts to ±0.001 in (±0.025 mm) are quoted against the drawing — see our tolerance standards. Flatness and parallelism on plates and sealing faces are verified on the CMM before parts leave the floor.
Finishing is coordinated with machining: anodizing (Type II and Type III hard coat), bead blast, nickel and zinc plating, powder coat, passivation for stainless, and laser marking. Call it out on the drawing and it appears in your quote with lead time included.
Materials We Mill
Aluminum (6061, 7075, 5052, MIC-6) accounts for the bulk of our milling work; we also run stainless (303, 304, 316L), carbon and alloy steels (1018, 4140), tool steel, titanium (Grade 2, Grade 5), brass, copper, and engineering plastics including Delrin, PEEK, polycarbonate, nylon, ABS, and Ultem. Material certificates are available on request, and saw-cut stock is traced to the mill cert for orders that require it. Full list on the materials page.
How to Get the Best Milling Quote
A few things on the drawing directly move milling cost:
- Internal corner radii — the largest radius you can accept means a larger tool, faster cutting, and lower cost
- Pocket depth — keep depth under 4× the corner radius where possible; deeper pockets need long-reach tools and slow passes
- Tolerances — tighten only what functionally matters; blanket tight tolerances multiply programming and inspection time
- Threads — standard thread sizes and reasonable depths tap or thread-mill quickly; exotic threads need special tooling
- Wall thickness — thin walls below 0.040 in (1 mm) may need stress-relieved roughing passes to stay flat
Not sure whether a feature is driving cost? Send the drawing — DFM feedback is part of every quote, and we will tell you which callouts are adding money and what to change to remove it. Most milling quotes come back with at least one practical suggestion you can accept or decline. All parts pass dimensional inspection before shipment; see quality inspection.
Start Your RFQ
Upload STEP files and drawings for pricing and lead time, typically within 1–2 business days.
Get an Instant Quote →