Acrylic Plastic Machining

Your guide to Acrylic Plastic Machining

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Transparent thermoplastic with excellent strength and optical clarity

Excellent glass substitute

10-24 times the impact resistance of glass

Acrylic is commonly known by its brand name, Perspex®. Its excellent strength and optical clarity make it a great alternative to glass and it even outperforms glass in several aspects. It can however be challenging to machine.

This guide will take you through the main attributes, common applications, notes for designers and suitable finishing and treatments, as well as UK stock sizes and property tables. Don't forget to bookmark the page so you can refer back later.

If you are interested in acrylic machined parts, please scroll to the bottom of the page for more information about our service and to request a quote.

Acrylic Guide: Properties, Applications and Design Considerations

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What is acrylic?

Acrylic, commonly known as the brand name Perspex®, is a transparent thermoplastic with excellent strength and optical clarity and is thus widely used as a glass substitute; though it outperforms glass in several aspects.

Similar in characteristics to Polycarbonate, Acrylic plastic has a lower impact strength but still boasts 10-24 times the impact resistance of glass. It is also more flexible and lighter than glass.

Acrylic can present some challenges in machining but Penta Precision has decades of acrylic machining experience so you are in safe hands.

Cast Acrylic is preferable over Extruded Acrylic for machining purposes as it is more rigid and less prone to stress cracking after machining.

As well as a sharp cutting edge and slow feed rates, we also use plenty of coolant to aid lubrication, remove swarf and help keep the acrylic below its melting point.

You may also see Acrylic referred to as:

Trade names: Perspex, ACRYLITE®, Plexiglas®, Polycast, Lucite®, Optix®, Crystallite, Acryglas XT®, Kerrock®, Seta-LED®, Acrycast®, Setasand®, Green Cast®
PolyMethyl MethAcrylate (PMMA)

Industry Examples: Aerospace | Electronics Automotive Medical | Transportation

Typical Components & Applications: Transparent manifolds | As an alternative to glass | Guards | Housings | Electronics components | Aerospace components | Household items | Appliances | Lenses | Automotive trim | Windows | Lighting fixtures | Furniture | Toys | Signage | Medical devices | Enclosures | Sound barriers

Main Attributes:

Excellent optical clarity and light transmission properties
Abrasive resistance comparable to aluminium
Good chemical resistance
Good flexural strength
Around half the weight of glass and easier to process
Readily available and reasonability cost effective
Excellent weatherability and resistance to sunlight
Excellent dimensional stability
Subject to stress cracking
Combustible
Available in transparent or opaque forms

More flexible and shock resistant than glass
Good insulator
Good acoustic properties (can act as sound barrier)
BPA free
Easy to solvent bond
UV resistant
FDA Compliant grades available
Available in all colours imaginable
100% recyclable
Available with a range of coatings including abrasion resistant, bullet resistant and electrostatic dissipative (ESD)

Note For Designers:

Although Acrylic has similar properties to polycarbonate and is used in similar applications (i.e. as impact resistant alternative to glass), it can be used when the extremely high impact strength of polycarbonate is not required. It is also BPA free which polycarbonate is not typically (although BPA-free polycarbonates are becoming available).

Once machined, Acrylic will become frosted. It will therefore require polishing to restore clarity. This process needs to be factored into time and cost. Please see the ‘finishing & treatments’ tab for further information about the processes we can facilitate.

Finishing & Treatments:

Vapour polishing – to reduce surface roughness and improve optical clarity

Mop polishing – to improve surface finish and appearance. Requires removal of material

Heat annealing - to ensure continued stabilitiy over time

See our Finishing Processes page for further information on services that we can facilitate.

Can we meet your acrylic machining needs? Contact us now

UK Stock Sizes

Acrylic UK Stock Sizes

Please note we do not supply stock material, the information provided is purely for design and research purposes.

Acrylic is a readily available engineering plastic. It is available in a wide range of sizes and thicknesses in both extruded and cast sheet, rod and tube. There are solid and opaque variations as well as an extensive range of colours.

Example Acrylic Stock Sizes

Stock sizes will vary depending on supplier. Please get in contact to discuss further.

Type	Size	Length
Rod	Ø2 - Ø200mm in 2mm increments	3,000mm and 2,000mm
Sheet	2, 3, 4, 6, 8, 10, 12, 15, 20 and 25mm thickness	3,000mm and 2,000mm
Block	35, 40, 50, 60, 70, 80mm thickness	3,000mm and 2,000mm

Technical Properties

Acrylic Technical Properties

Cast Acrylic Tube & Rod Properties (clear/translucent)

Mechanical Properties	Value	Parameter	Norm
Modulus of Elasticity	3300 MPa	23°C	D790
Tensile Strength	110 MPa	-40°C	D638
	80 MPa	20°C	D638
	40 MPa	70°C	D638
Elongation at Break	5.5%		DIN 53455
Flexural Strength	115 MPa	80x10x4mm³	D790
Compressive Yield Stress	110 MPa
Impact Strength (Charpy)	15 kJ/m²		DIN 53453
Notched Impact Strength (IZOD)	1.6 KJ/m²		DIN 53453
Indentation Hardness	175 MPa	961/30	DIN 53456

Thermal Properties	Value	Parameter	Norm
Forming Temperature	160-175°C
Ignition Temperature	425°C		DIN 51794
Heat Deflection Temperature Under Load	105°C	1.8 MPa
Heat Deflection Temperature Under Load	113°C	0.45 MPa
Service Temperature	80°C	Max
Thermal Expansion (CLTE)	0.07 mm/m°C		DIN 53752
Specific Heat	1.47 J/(g*K)
Thermal Conductivity	0.19 W/(K*m)	20°C	DIN 52612

Electrical Properties	Value	Parameter	Norm
Volume Resistivity	>10¹⁵Ω. cm		DIN VDE 0303
Dielectric Strength	~30 kV/mm	1mm	DIN VDE 0303

Other Properties	Value	Parameter	Norm
Water Absorption	41 mg	24h (20°C)	DIN 53495
Flammability	B2	>2mm	DIN 4102
Density	1.19 g/cm³

Cast Acrylic Sheet Properties (clear/translucent)

Mechanical Properties	Value	Norm
Modulus of Elasticity (tensile test)	3000-3400 MPa	ISO 527
Tensile Strength	72 MPa	ISO 527
Elongation at Break	4-6%	ISO 527
Flexural Strength	125 MPa	ISO178
Compression Strength	120 MPa	ISO604
Impact Strength	12-15 kJ/m²	ISO 179-1

Thermal Properties	Value	Norm
Heat Stability - Vicat B	110°C	ISO 306
Forming Temperature	130-190°C
Service Temperature (MAX)	80°C
Thermal Expansion (CLTE)	0.07M/mm°C	ISO 11359-2
Specific Heat	1.47KJ/kg°C	ISO 11357-4
Thermal Conductivity	0.19W/m°C	DIN 52612