Acrylic (PMMA)
The clearest plastic we stock, and the one that stays clear outdoors. Harder and glossier than polycarbonate, and more brittle. In sheet, rod and tube.
Cast acrylic typical properties
Figures are for cell-cast acrylic sheet (Plaskolite OPTIX G-Series). These are typical values, not a specification. The datasheet behind each figure is linked in its row: the manufacturer’s where one publishes the figure, a distributor’s otherwise. Figures vary by supplier and test method, so confirm against the datasheet for the grade and stock form you are designing with.
| Property | Typical value |
|---|---|
| Density | 1.19g/cc |
| Tensile strength | 10,500psi ultimate, no yield pointASTM D638Plaskolite OPTIX G-Series Cell Cast acrylic PDS461 (11/2023) (opens in a new tab) |
| Tensile modulus | 450,000psi |
| Flexural modulus | 450,000psi |
| Hardness | 100Rockwell M |
| Izod impact, notched | 0.3ft-lb/in |
| Max continuous service temp | 180°F manufacturer rating ('Max Recommended Continuous Service Temp')Plaskolite OPTIX G-Series Cell Cast acrylic PDS461 (11/2023) (opens in a new tab) |
| Heat deflection temp @ 264 psi | 205°F |
| Water absorption, 24 h | 0.2% The datasheet does not print the immersion time; the ASTM D570 default of 24 h is assumed. |
| Thermal expansion (CTE) | 3.9×10⁻⁵ in/in/°F |
| FDA food contact | Grade dependent Clear sheet meets the extractive tests of 21 CFR 177.1010(b) with one exception for ultraviolet absorbers in 50% alcohol. Most coloured sheet is not compliant. |
Figures are for cell-cast sheet. Extruded sheet, rod and tube differ.
What Acrylic is
Crystal clear thermoplastic with excellent optical properties and weather resistance.
Acrylic or polycarbonate
The two get quoted against each other constantly and they fail in opposite directions. Acrylic is harder, holds a polished edge, resists scratching and does not yellow outdoors — which is why it wins on display, signage and lighting. Polycarbonate takes the impact that shatters acrylic, which is why guarding and safety glazing go the other way. If nothing is going to hit it and it has to still look good in five years, acrylic is usually the answer.
Machining Acrylic
Acrylic is brittle at the cutter: it chips and cracks rather than smearing, which is the opposite failure mode to polycarbonate. Sharp tooling, high speed and a steady light feed give the cleanest result, and it is the one common plastic that will flame-polish to an optically clear edge. Drilling is where parts are lost — a standard twist drill grabs as it breaks through and cracks the sheet, so the point geometry has to be modified and the material backed up. It also holds casting and moulding stress and crazes when solvents reach a stressed edge.
Need Acrylic parts machined to print?
Send us a drawing and we will quote it. Precision plastic machining in Linden, New Jersey since 1968.