CNC Milling Services for Custom Precision Parts
Precision CNC milling services for complex parts in aluminum, steel, titanium, and engineering plastics.
Reviewed by PiPrecision Engineering Team on March 10, 2026
Overview
PiPrecision machines custom metal and plastic components using 3-axis, indexed 3+2, and simultaneous 5-axis strategies selected from the part geometry, datum scheme, volume, and inspection requirements. Each quotation identifies the reviewed process scope; machine travel, catalogue accuracy, and a single tolerance value are not finished-part guarantees.
Choose the Milling Approach from the Part—not the Axis Count
PiPrecision reviews geometry, datum relationships, tool access, surface requirements, quantity, and inspection needs before selecting a setup strategy.
| Approach | Best suited to | Important review points |
|---|---|---|
| 3-axis milling | Prismatic plates, brackets, pockets, and accessible features | Setup count, pocket depth, internal radii, and workholding access |
| Indexed 3+2 milling | Multi-face parts and compound-angle features | Datum transfer, rotary clearance, and feature relationships between orientations |
| Simultaneous 5-axis milling | Contoured surfaces and features requiring continuous tool orientation | Collision control, tool reach, surface verification, and programming cost |
The published machine work envelope is a travel reference, not a guaranteed finished-part size. Fixtures, rotary axes, tool reach, stock size, part weight, and inspection access reduce usable capacity.
DFM and Inspection Questions We Review Before Quoting
A useful milling quote depends on the complete model, controlled drawing, and acceptance requirements—not a tolerance value by itself.
- Deep pockets, narrow slots, minimum inside radii, long-reach tools, and chip evacuation.
- Thin walls, residual material stress, stock condition, clamping force, and free-state inspection.
- Datum selection, GD&T relationships, setup changes, and access to measure critical features.
- Surface texture before finishing, masked features, edge breaks, and post-finish dimensional requirements.
- First article, CMM report, material certificate, and production inspection frequency.
Documented Project Examples
Results below are specific to the linked project, part, volume, process, and inspection scope. They are not universal capability guarantees.
Engineering Resources
Use these guides to prepare drawings, tolerances, finish requirements, and inspection expectations before RFQ.
CNC Milling Accuracy Guide
How geometry, setup, material, and inspection determine achievable accuracy.
Read more →Aluminum 6061-T6 Machining Guide
Alloy selection, tolerances, finishes, and DFM considerations.
Read more →CNC Machining DFM Guide
Practical design choices that reduce machining risk and cost.
Read more →Capabilities
These are general, drawing-reviewed capabilities. The quotation confirms the applicable process, tolerance, inspection method, evidence, and any outside operation for the specific part.
Standard 3-axis vertical machining for prismatic parts
Rotary table integration for complex geometries
Full 5-axis for intricate contours and reduced setups
Up to 15,000 RPM spindle speeds for aluminum
Capable of machining HRC 60+ hardened steels
Features as small as 0.1mm in diameter
Quality Assurance
- CMM (Coordinate Measuring Machine) inspection
- Surface roughness measurement (Ra, Rz)
- First Article Inspection Reports (FAIR) available
- Statistical Process Control (SPC) for production runs
Specifications
| Maximum Work Envelope | 800mm × 600mm × 500mm (31.5" × 23.6" × 19.7") |
| Positioning Accuracy | ±0.005mm (±0.0002") |
| Repeatability | ±0.003mm (±0.00012") |
| Standard Tolerance | ±0.05mm (±0.002") per ISO 2768-m |
| Precision Tolerance | ±0.005mm (±0.0002") available |
| Drawing-Reviewed Tolerance | ±0.005mm (±0.0002"), subject to drawing review |
| Surface Finish (Standard) | Ra 1.6 μm (63 μin) |
| Surface Finish (Fine) | Ra 0.4 μm (16 μin) |
| Surface Finish (Mirror) | Ra 0.1 μm (4 μin) |
| Minimum Feature Size | 0.1mm (0.004") |
| Minimum Wall Thickness | 0.5mm (0.020") |
Published capabilities are indicative and subject to drawing review.
Equipment
Primary Machines
- HAAS VF-4SS — 5-Axis, 12,000 RPM, 30-tool ATC
- DMG MORI DMU 65 monoBLOCK — 18,000 RPM, integrated 5-axis
- HAAS VF-2SS — 3-Axis, 12,000 RPM, high-speed machining
- Brother Speedio S1000X1 — 16,000 RPM, rapid positioning
Inspection Equipment
- Hexagon Global Classic SR CMM — Coordinate measuring machine
- Mitutoyo Surftest SJ-210 — Surface roughness tester
- Vision Measurement System — For small features
Materials
| Material | Grades | Applications |
|---|---|---|
| Aluminum | 6061-T6, 7075-T6, 5052, 6082-T6, etc. | Aerospace, electronics, automotive |
| Stainless Steel | 303, 304, 316, 17-4PH, 420, etc. | Medical, marine, food processing |
| Steel | C45, Q235, 1018, 4140, A2, D2, etc. | Tooling, industrial, automotive |
| Titanium | Grade 2, Grade 5 (Ti-6Al-4V) | Aerospace, medical implants |
| Brass & Copper | C360, H59, C464, C110, T2, etc. | Electrical, decorative, plumbing |
| Engineering Plastics | ABS, POM, PEEK, PC, Delrin, Nylon, etc. | Medical, electrical insulation |
Sample Parts
Why Choose PiPrecision
- 6+ yrs Export Experience
- 24h CAD Quote Review
- 1 piece Minimum Order
- 2 weeks Production Lead Time
Need CNC Milling Service?
Initial review is targeted within 24 hours for a complete RFQ. Orders from one prototype are supported.
Request QuoteCNC Milling Service FAQs
Process-specific answers from the PiPrecision Engineering and Quality teams.
What part sizes can PiPrecision CNC mill?
The published 800 × 600 × 500 mm figure is a machine travel or work-envelope reference, not a guaranteed finished-part size. Usable capacity is smaller when fixtures, rotary axes, tool length and access, part loading, material weight, feature depth, or inspection access consume the envelope. Send the complete part and stock dimensions; engineering must confirm the machine, setup, reach, workholding, and tolerances for every large, thin, heavy, or distortion-sensitive part.
Answer owner: PiPrecision Engineering Team
When is 5-axis milling preferable to 3-axis or 4-axis machining?
Indexed 3+2 machining positions the part and cuts with the rotary axes locked; simultaneous 5-axis machining moves linear and rotary axes together during the cut. Either can reduce setups for multiple faces, compound angles, or difficult tool access and may improve relationships between features made in one setup. Simultaneous 5-axis work adds programming, collision-control, toolpath, and verification demands, so it is not automatically more accurate or economical. PiPrecision selects the method from geometry, tolerance, surface, quantity, and inspection needs.
Answer owner: PiPrecision Engineering Team
Can PiPrecision mill thin walls and distortion-sensitive parts?
Thin walls may be feasible, but wall thickness alone does not predict stability. Material condition and residual stress, wall height and unsupported length, stock shape, tool pressure, heat, workholding, and removal sequence all matter. Engineering may recommend balanced roughing, intermediate stress relief, temporary supports, sacrificial features, revised corner radii or tolerances, or an agreed restrained-versus-free-state inspection method. Submit the full geometry rather than relying on a generic minimum-wall figure.
Answer owner: PiPrecision Engineering Team
Which materials can be CNC milled?
Common candidates include aluminum, stainless steel, carbon and alloy steels, titanium, brass, copper, and engineering plastics. Feasibility is confirmed by exact grade, temper or heat-treatment condition, stock form, dimensions, quantity, required certificates, and final finish. Substitute grades are not assumed. Plastics may also require moisture-conditioning, temperature, stress-relief, or inspection-state requirements because they can move with humidity, temperature, and machining stress.
Answer owner: PiPrecision Engineering Team
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