Extruded and Cast Acrylic
Cutting with a knife or scriber
Acrylic sheet up to 4.5mm thick can be cut by a method like those when cutting glass. Using a scribing knife, a metal scriber, an awl, which is a long sharp tool used to punch small holes through plastic, or a utility knife to score the sheet. Draw the scriber several times along a straight edge firmly in place. Then clamp the sheet and hold it rigidly under a straight edge with the scribe mark hanging just over the edge of the table. Apply a sharp downward pressure to break the sheet along the scribe line. Scrape the edges to smooth any sharp corners. However, this method is not recommended for thicker material or long breaks.
Cutting with Power Saws
Special blades are available for cutting into Acrylic. Otherwise it is advised to use blades designed to cut Aluminum or copper. Teeth should be fine, of the same height, evenly spaced, and with little or no set.
Table and Circular Saws
Use hollow ground high speed blades with no set and at least 5 teeth per inch. Carbide tipped blades with a triple chip tooth will give the smoothest cuts. Set the blade height about 3mm above the height of the material, this will reduce edge chipping. When using a handheld circular saw, clamp the sheet to the work surface and use a wood length of 25” X 75” to distribute the clamping pressure and act as a guide for the saw. Feed the work slowly and smoothly. Lubricate the blade with soap or beeswax to minimize gumming from the masking adhesive. Be sure the saw is up to full speed before beginning the cut. Water cooling the blade is suggested for thickness greater than 6mm, especially if edge cementing will be performed.
Use metal or Plastic cutting blades. The blades you use for cutting Acrylic should never be used for any other material. Cut at a high speed and be sure the blade is up to full speed before even beginning the cut.
Good results with Hand Saws are possible, but very difficult. Be sure the Acrylic is clamped to prevent flexing. Flexing at the cut may cause cracking or breakage.
Routers and Shapers
Use single fluted bits for inside circle routing and double fluted bits for edge routing. At the high speeds at which routers operate, it is critical to avoid all vibration. Even small vibrations can cause crazing and fractures during routing.
For the best results, use drill bits designed specifically for Acrylic. Regular twist drills can be used but need modification to keep the blade from grabbing and fracturing the plastic. Modify the bit by grinding small flats onto both cutting edges, so the bit cuts with a scraping action. If the drill is correctly sharpened and operated at the correct speed, two continuous spiral ribbons should emerge from the hole being drilled.