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CNC Machining Services
Precision CNC polycarbonate parts for optical, structural, and industrial applications. Tight tolerances with controlled machining processes that reduce crazing, stress cracking, and surface defects.
General-purpose, optical, UV-stabilised, and glass-filled grades available
Full DFM review and dimensional inspection report on every order
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FastPreci produces custom polycarbonate parts from single prototypes to full production runs. There is no minimum order quantity.
Flat and contoured parts run on 3-axis centres. Complex geometry runs on 5-axis centres.
Cylindrical polycarbonate parts—tubes, rods, lens holders, and housings—are turned on lathes.
Thermoplastic-specific drill geometry prevents cracking during hole machining.
Bevels, chamfers, and radiused edges on enclosures and display panels require controlled tool paths.
Polycarbonate retains internal stress after machining and is more sensitive to chemical exposure than acrylic. Stress cracking and surface crazing are controlled through stable machining parameters and process control.
Sharp, polished carbide tools designed for thermoplastics reduce heat build-up and improve surface quality. Standard metal-cutting tools are not used for polycarbonate machining.
Spindles run between 10,000 and 16,000 RPM for machining polycarbonate. Feed rate is reduced at internal corners, thin walls, and entry points—where stress concentrates—to prevent micro-cracking.
Flood coolant is avoided during polycarbonate machining due to the risk of solvent stress cracking. Compressed air and light mist are used for chip removal and heat control.
Parts with tight tolerances or complex geometry undergo annealing at 110–120°C after machining—higher than the acrylic cycle. This releases residual cutting stress. Required for features tighter than 0.03 mm.
Critical dimensions are checked mid-process with calibrated gauging. Corrections are applied before the run continues, maintaining consistent batch results.
The facility runs at controlled temperature. Polycarbonate stock is conditioned before machining to ensure dimensional stability.
Freshly machined polycarbonate surfaces may show light haze and visible tool marks. Finishing method is selected based on part geometry and optical requirements.
Method | What It Does | Best For |
Progressive Sanding | Graded abrasive from 400 to 2000 grit removes tool marks | Flat face preparation before polishing |
Buffing and Polishing | Rotary cloth with polishing compound produces high clarity | Edges and external flat faces |
Vapour Polishing | Solvent vapour reflows the surface layer to remove haze | Internal bores, channels, and complex contours |
Flame Polishing | Controlled torch melts the top surface layer to a clear finish | Curved edges and radiused profiles |
Hard Coat | Abrasion-resistant coating applied to the machined surface | Parts in high-wear or outdoor environments |
As-Machined | Deburring only, no surface treatment | Internal components and non-visible faces |
Polycarbonate machining requires design choices that account for thermal expansion, stress concentration, and dimensional stability. Most failure modes are preventable at the design stage.
Sharp internal corners increase stress concentration under load. A minimum internal radius of 0.5 mm is recommended, with 1.0 mm preferred for snap fits and load-bearing features.
PC plastic walls below 1.5 mm deflect under cutting load. Use unilateral tolerances on thin-wall features. Fixturing is confirmed before production to ensure wall support.
Polycarbonate expands more than metal under temperature change. Clearance fits are recommended when mating with aluminium or steel to reduce cracking risk during thermal cycling.
Annealing may cause minor dimensional movement. Features tighter than 0.03 mm are typically measured after the annealing cycle is complete.
Directly tapped threads should use a minimum engagement depth of 2.5× the thread diameter. Threaded inserts are recommended for high-load or high-cycle assemblies.
Polycarbonate-to-polycarbonate contact areas near fastener holes and press-fit zones should include a minimum 0.1 mm clearance to reduce stress cracking risk. Fastener torque requirements are reviewed during DFM.
The grade of polycarbonate directly affects machinability, optical performance, and long-term stability. Grade selection is confirmed during DFM review.
Standard material for structural enclosures, covers, and housings used across most CNC applications.
Suitable for general industrial and electronic components
Higher-purity PC designed for applications requiring improved clarity and surface finish.
Suitable for lenses, windows, and light-guiding parts
Formulated for long-term exposure to sunlight and outdoor environments.
Ideal for outdoor enclosures and protective covers
Reinforced grade for improved stiffness and dimensional stability in structural applications.
Requires adjusted tooling due to abrasive filler content
Certified PC grade for electrical and electronic applications requiring fire safety compliance.
Meets UL94 V-0 / V-2 requirements
Suitable for electrical housings and connector systems
Different industries rely on polycarbonate for its balance of impact resistance, optical clarity, and thermal stability.
We machine UV-stable PC plastic parts for electronic enclosures and display assemblies.
We produce CNC polycarbonate parts for industrial inspection and automation systems.
Machine guards and safety covers for operator protection
Vision system windows for real-time inspection processes
Sensor housings requiring clear optical access
Fixtures and jigs for production line accuracy
Custom polycarbonate parts improve impact resistance for robotic systems.
Transparent joint and actuator covers for motion visibility
Sensor mounts requiring structural rigidity and optical access
Lightweight enclosures for onboard electronic systems
Protective guards for high-speed moving components
Biocompatible CNC polycarbonate parts for clinical and diagnostic equipment give better dimensional stability.
Impact-resistant polycarbonate parts for automotive testing, lighting, and interior applications.
We machine polycarbonate prototype and production parts for aerospace ground support and cabin applications.
Selecting between polycarbonate vs acrylic and ABS depends on impact load, operating temperature, and optical requirements.
Property | Polycarbonate | Acrylic | ABS |
Light Transmission | 88% | 92% | Opaque |
Impact Resistance | Extremely High | Medium | High |
Machinability | Good | Excellent | Excellent |
UV Resistance | Requires UV grade | Excellent without coating | Poor |
Operating Temperature | Up to 120°C | Up to 80°C | Up to 80°C |
Weight | 1.20 g/cm³ | 1.19 g/cm³ | 1.05 g/cm³ |
Scratch Resistance | Lower than acrylic | Moderate | Low |
Chemical Resistance | Moderate | Good | Good |
Machining Cost | Medium | Low to medium | Low |
Choose acrylic for maximum optical clarity and scratch resistance with low impact loads. CNC polycarbonate is the choice where impact resistance, temperature performance, or structural load takes priority. ABS suits opaque housings where cost and weight decide.
3–5 business day standard lead time. Rush production available on request.
Down to 0.02 mm on critical features. 5-axis machining and PC-specific tooling on every clear polycarbonate parts.
Our team machines general-purpose, optical, UV-stabilised, glass-filled, and flame-retardant PC plastic grades, with process parameters set for each grade's response to cutting forces, heat, and chemical exposure.
Spindle speeds, feed rates, and coolant for our machining polycarbonate operations are set specifically for PC. Metal-cutting parameters are never applied.
ISO 9001:2015 certified. Dimensional inspection, visual inspection, first article reporting, and material traceability on every CNC polycarbonate order.
Every project includes a DFM review at no charge. Fracture risk, tolerance conflicts, and grade issues are resolved before the first cut.