logo junying metal fabrication已改1
CNC MACHINING MATERIALS

Acrylic

At a glance

ProcessesLead TimeColorsTolerancePriceApplications
CNC Mill
CNC Lathe
As fast as 3 daysOptically clear, opaqueWith drawing: as low as +/- 0.005 mm
No drawing: ISO 2768 medium
$tanks, panels, and optical applications

About the Material

Acrylic is a scratch-resistant plastic, available optically clear or opaque. It is often used for tanks, panels, and optical applications. It can be somewhat brittle in thin walled areas, so it is not recommended for delicate or complex geometries.

This plastic is also known as PMMA, an abbreviation of its full chemical name, polymethyl methacrylate, as well as by the trade names Plexiglas and Lucite.

Material Properties

 

Tensile Strength

Elongation at Break

Hardness

Density

Maximum Temp

McMaster Part
8,000 PSI6%Rockwell M951.19 g/㎤
0.043 lbs / cu. in.
170° F8560K274

Material Finish

Acrylic is transparent or opaque (black, white, and a variety of colors) in its unfinished state.  Clear acrylic will take on more of a frosted translucent appearance when machined, though can be smoothed again to an optically clear state using various finishing methods.

 

Design Recommendations

 

Min Wall Thickness

Min End Mill Size

Min Drill Size

Max Part Size

Undercuts

Radii : Depth
0.5 mm0.8 mm (0.03 in)0.5 mm (0.02 in)1200 x 500 x 152 mm[(x,y,z] (mill) 152 x 394 mm [d,h] (lathe)Square profile, full radius, dovetail profilesDepth must not exceed 12x drill bit diameter.
For end mills, depth must not exceed 10x drill bit diameter.

Cost Saving Tip

To reduce costs, limit the number of part setups, the number of inspection dimensions or tight tolerances, and deep pockets with small radii.

Acrylic FAQs

Yes, acrylic is a common material used in CNC machining. Acrylic is a scratch-resistant plastic, which in thin-walled areas can be fairly brittle. For this reason it isn’t ideal for parts that require delicate or complex shapes.

 
 

These five tips will help you avoid difficulties and maintain a smooth cut when using CNC to cut acrylic:

  1. To avoid vibration, make sure the workpiece is properly secured.
  2. Use a bit specifically designed to cut acrylic.
  3. Larger bit sizes tend to perform best
  4. Cut at a steady rate through the acrylic as quickly and steadily as you can while maintaining control.
  5. Keep the acrylic cool by putting it in a freezer for an hour prior to making the cuts.
 
 

Acrylic is transparent and is frequently used as a lightweight substitute for glass or for light pipes. Other uses include plastic parts such as car lights, light tubes, tanks, panels and optical applications.

 

At least 18,000 RPMs is the recommended speed for cutting acrylic. Although higher speeds are possible, you may need to adjust your feedrate to prevent the material from melting from the heat. This also depends on the diameter of the tool being used.

 
 
YOU MIGHT ALSO BE INTERESTED IN
CNC Programming

CNC (Computer Numerical Control) machining is an automated, subtractive manufacturing process where a CNC machine is controlled with a set of commands that, when followed, will produce a part. CNC operators create….

pound a peg

Too Tight or Perfect Fit? When to Use Press Fits in Assemblies

example dowel pin interference fit table