We manufacture OEM CNC machined PMMA parts in China for buyers who need precise, transparent acrylic components rather than off-the-shelf standard shapes. Every part is cut to a customer drawing from cast or extruded PMMA stock, and the tool paths, fixturing, feeds and finishing are tuned to the way acrylic actually behaves instead of treating it as a soft stand-in for metal. The same workflow supports custom CNC machined acrylic parts in China across clear, translucent, light-diffusing and tinted grades, from one-off prototypes to repeat production batches.
PMMA — poly(methyl methacrylate), universally known as acrylic — delivers glass-like optical clarity at roughly half the density of silicate glass, with much better resistance to impact. When it is machined with sharp geometry, controlled heat and gentle clamping, it cuts cleanly and polishes to an optically clear edge. The modules below explain the material profile, the way national material standards and regional trade names map to one another, our machining and finishing capability, realistic tolerances, and the design rules that keep an acrylic part dimensionally stable long after it leaves the machine.
PMMA is an amorphous, rigid thermoplastic. The values below are typical ranges taken from published PMMA material data; exact numbers move with grade (general-purpose, heat-resistant or impact-modified), production route (cast versus extruded) and color. Understanding these properties is what allows custom CNC machined acrylic parts in China to be designed for clarity, tight dimensions and long-term stability instead of trial and error on the machine.
Clear PMMA transmits roughly 92% of visible light through a 3 mm section, with a refractive index near 1.49 and very low haze. A properly polished edge becomes transparent and lens-like, which is why the material is preferred for light guides, lenses and inspection windows.
With a density of 1.18–1.19 g/cm³, PMMA is about half the weight of silicate glass of the same volume. Transparent covers and guards become lighter, easier to mount and less demanding on supporting structures.
Tensile strength typically lands at 60–77 MPa, flexural strength at 90–120 MPa and flexural modulus near 2.8–3.3 GPa. Elongation at break is only 2–6%, so the material is stiff and dimensionally firm but notch-sensitive — internal radii matter.
Glass transition sits near 105–115 °C and heat-deflection temperature at 1.8 MPa is typically 85–100 °C depending on grade. Continuous service is conservative at about −40 to +80 °C; the coefficient of linear thermal expansion is 70–80 ×10⁻⁶/°C, so clearances must allow movement.
PMMA keeps its clarity, gloss and color unusually well outdoors and resists yellowing under long-term UV exposure, while blocking ultraviolet light below roughly 300 nm. This makes it a natural fit for exterior lamp lenses, glazing and outdoor instrumentation.
PMMA is a good electrical insulator and absorbs only about 0.2–0.3% water in 24 hours. It tolerates weak acids, weak alkalis and most neutral detergents, but aromatic or chlorinated solvents, ketones and alcohol can trigger stress cracking — alcohol wipes should never be used on a finished part.
Cast acrylic is polymerized in a mold or cell. It carries very low residual internal stress, offers the best optical clarity and chemical resistance, and behaves predictably under cutting and polishing. It is the preferred starting point for tight-tolerance OEM CNC machined PMMA parts in China that need transparent edges, flatness or thin walls. As a trade-off, raw cast sheet carries a wider as-supplied thickness tolerance.
Extruded acrylic is formed continuously, so it arrives with a more uniform thickness, a lower price point and good thermoforming behavior. Because extrusion freezes in more residual stress, machined extruded parts need gentler clamping, symmetric stock removal and, where geometry demands it, a stress-relief cycle after roughing to stop movement or crazing later.
Buyers of custom CNC machined acrylic parts in China often encounter different names for what is chemically the same polymer. PMMA is designated under national material standards, while resin and sheet producers sell it under registered trade names with their own grade codes. The table maps the principal markets, the material designation references used there and the trade names a drawing or bill of materials is likely to quote.
| Market / region | Raw-material designation reference | Representative commercial trade names | Typical grade coding |
|---|---|---|---|
| International | ISO 24026-1:2020 designation system for PMMA moulding and extrusion materials (succeeds the withdrawn ISO 8257-1:1987); ISO 7823 series covers cast sheet | Common designation basis adopted by many national systems | Classified by flow, thermal and optical behavior |
| United States | ASTM D788 for moulding and extrusion compounds; ASTM D4802 for acrylic plastic sheet | ACRYLITE (Americas brand of the Röhm group), LUCITE (originally a DuPont trade name, now with Lucite International) | Producer series: general-purpose, high-heat, impact-modified |
| United Kingdom & Ireland | BS EN ISO 24026-1 (ISO text adopted as a British/European standard); legacy BS grades | PERSPEX (originally introduced by ICI in the UK, now held by Lucite International) | Named by color, finish and grade series |
| Continental Europe | DIN EN ISO 24026-1 in Germany and equivalent NF/EN adoptions in France and neighboring markets | PLEXIGLAS (Röhm GmbH, Germany — used across Europe, Asia, Africa and Australia), ALTUGLAS (a French-origin PMMA range) | Producer numbers for cast, extruded and optical stock |
| Japan | JIS K 6717-1 for PMMA moulding and extrusion materials | SUMIPEX (Sumitomo Chemical), ACRYPET (Mitsubishi Chemical), DELPET (Asahi Kasei), PARAPET (Kuraray) | Letter-number series such as HT, IH and IF types |
| South Korea | Korean KS standards that adopt the ISO designation framework | LG / LX MMA PMMA resin ranges | HP202, IH830, IF850-style grade codes |
| China | GB/T 7134 for cast industrial PMMA sheet; the moulding/extrusion designation series is aligned with ISO 24026 and developed with domestic resin producers | ACRYREX (Chi Mei, produced at its Zhenjiang base), plus domestic resin ranges such as Wanhua and Shuangxiang | CM-205 / CM-211-style heat-resistant codes and producer-specific codes |
| South America | ABNT NBR adoptions of the ISO PMMA designation in Brazil and neighboring markets | ACRILEX (a Brazilian-market PMMA range) | Regional producer grade coding |
PMMA, acrylic and “organic glass” describe the same polymer family, while PLEXIGLAS, PERSPEX, ACRYLITE and the rest are regional trademarks. A different name rarely means a different chemistry; it usually reflects the producer and the market.
Within each brand, grades split into general-purpose, heat-resistant, impact-modified and optical/extrusion types. The grade changes HDT, flow and impact behavior, so it should be selected before tool paths are planned.
Sheet standards such as ISO 7823, ASTM D4802 and GB/T 7134 describe cast or extruded semi-finished sheet, while ISO 24026, ASTM D788 and JIS K 6717 describe moulding and extrusion materials — pellets and compounds.
Name a producer and grade, or simply give property targets — light transmission, heat resistance, color and production route. We then machine the designated stock or a documented equivalent and keep the raw-stock grade record with the batch.
Acrylic rewards a specific cutting strategy: sharp single-flute (O-flute) geometry, climb milling, high spindle speed with a measured feed, compressed-air chip evacuation and absolutely no melting heat built into the cut. The six process blocks below cover the operations used to turn PMMA sheet, rod or tube into finished custom CNC machined acrylic parts in China.
Pockets, profiles, cavities, manifolds, curved lens surfaces and multi-face components. Sharp O-flute tooling and climb milling leave a clean, low-stress cut, while air blast clears chips before they can weld to a warm edge.
Sleeves, bushings, rollers, spacers, light pipes and profiled rings turned from cast or extruded rod and tube. Fine finishing passes kept below roughly 0.1 mm produce a surface that polishes to full transparency.
Fine text, scales, serial marks, logos and micro-fluidic channels cut with small tools at controlled step-downs, so letter bottoms stay crisp and thin webs do not crack under tool pressure.
Bolt holes, reamed precision holes and tapped profiles use peck cycles and backing support to prevent exit-side breakout. Coarse threads are preferred in acrylic; metal thread inserts are recommended where a joint is assembled repeatedly.
Diamond, flame, vapor and mechanical polishing routes turn a milled or sawn edge transparent. The right route depends on edge geometry, batch size and the optical target, from functional clarity to a display-grade finish.
Solvent-cemented joints, stacked light guides, bonded panels and multi-part assemblies. Joint faces are machined to a controlled finish first, then bonded, masked and packed so protected surfaces survive transit scratch-free.
Most acrylic failures are drawn into the part before any tool touches it — sharp internal corners, unbalanced walls and over-tight clamping store stress that appears days later as a crack or a drifted dimension. The two panels below pair design guidance with the specification ranges a professional plastic machining cell can realistically hold on PMMA.
| General linear tolerance | ±0.10 mm |
| Critical-feature tolerance | ±0.05 mm |
| Turned diameter range | IT8 – IT7 by size |
| As-machined surface roughness | Ra 1.6 – 3.2 µm |
| Polished edge | optically clear |
| Flatness after stress relief | ≈ 0.10 mm / 100 mm |
| Sheet thickness range | ≈ 2 – 100 mm |
| Rod diameter range | ≈ Ø3 – Ø150 mm |
| Milling working envelope | up to ≈ 1000 mm |
| Turning working envelope | up to ≈ Ø200 mm |
The same machined geometry can be delivered with anything from a functional as-cut face to a display-grade transparent edge, and PMMA can also be supplied clear, custom-tinted, translucent or opaque. These six finishes are the standard options quoted for OEM CNC machined PMMA parts in China.
Fine, regular mill or turn marks at a typical Ra 1.6–3.2 µm. Suitable for functional faces, bonding surfaces and areas hidden from view, with protective film retained where possible.
A straight edge machined and polished to a true optical finish with minimal haze. It is the choice for light-guide edges, lenses and high-end display panels where light must cross the edge cleanly.
A quick thermal pass that glosses and clears a simple edge economically. Best for straightforward profiles where the highest optical grade is not required and the edge shape stays simple.
A controlled vapor process that levels the surface evenly across complex profiles and internal cut-outs, producing a consistent gloss where mechanical polishing cannot reach.
Sanded and buffed to a soft satin-to-clear surface that hides minor tool marks and fingerprints, often used on hand-held components and consumer-facing covers.
A uniform matte texture that scatters light evenly for LED diffusers and back-lit panels, removing hotspots while keeping the part translucent rather than fully clear.
A small selection of the acrylic components produced on the floor. Each is made to customer drawing; the images show representative part types rather than catalog stock.
Plastic parts need a different rhythm from metal work: dedicated tooling, clean fixturing and dimensional checks staged between roughing and finishing. The three floor views show the working environment, and the fourth panel summarizes how dimensions and appearance are checked as custom CNC machined acrylic parts in China move through the cell.
The combination of clarity, stiffness, weathering behavior and clean machining makes PMMA useful wherever a part must be transparent, protective or light-controlling. These eight sectors account for most repeat demand for OEM CNC machined PMMA parts in China.
Light guides, diffuser panels, lens arrays and lamp covers that direct or spread light with controlled transmission.
Transparent instrument housings, test fixtures, observation windows and trays where visibility of the process matters.
Lamp lenses, light pipes, interior trim and gauge covers that must stay clear and dimensionally stable in service.
Display windows, indicator lenses, control panels and polished cosmetic parts for handheld and desktop products.
Glazing, protective screens and interior panels for rail, marine and specialty vehicles where light weight and clarity help.
Sight glasses, guards and access panels selected in grades suited to repeated washing with neutral detergents.
Engraved plates, product stands, display cases and exhibition components with polished edges and custom tints.
Manifolds, inspection blocks, sleeves and spacers where engineers need to watch flow or alignment through the component.
The production route for custom CNC machined acrylic parts in China follows the same six controlled steps whether the order is a single prototype or a repeating batch. Each step has a defined output before the next one begins.
Geometry, tolerances, radii, wall balance and finish call-outs are reviewed against acrylic behavior, with manufacturability feedback returned before any metal is cut.
Cast or extruded PMMA, grade family, color, diffusion target and masking are confirmed, and sheet, rod or tube stock is cut to oversized blanks.
Sharp O-flute tools, climb-milling paths, soft-jaw fixturing and sacrificial support are planned so heat and clamp stress stay out of the part.
Bulk material is removed symmetrically; thin or flatness-critical parts receive a stress-relief cycle and slow cooling before the finish pass.
Light finish cuts, engraving, selected edge polishing, bonding and tint or texture work bring the component to its specified appearance.
Dimensions, roughness and appearance are checked, parts are cleaned without solvents, re-masked and packed to protect polished surfaces in transit.
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