The following are some of the common materials used in CNC plastic machining and their properties.  

ABS: Density 1.2, good toughness, can be bonded, can be baked at 70-80 degrees after spraying oil.  

PMMA: Density 1.3, more fragile, good transparency, can be bonded, can be baked at 65 degrees after spraying oil.  

PC: Density 1.2, high temperature resistance of 120 degrees, can be bonded, can be sprayed with oil, general transparency.

POM: Density 2, high strength and good toughness, cannot be sprayed with oil, cannot be bonded, wear-resistant.

PP: Density 1.1, high strength and good toughness, oil-sprayable, cannot be bonded.

Bakelite: Density 2, good toughness, high strength, does not spray oil, does not bond, can withstand 250 degrees high temperature.

Nylon: Density 1.2, good tenacity, high strength, no oil splashes, no adhesion.

475 plastic sheet: Density 1.2, relatively soft, poor toughness, can withstand 60-70 degrees high temperature.

Plastic King (PTFE): Density 2.2, cannot be bonded, cannot spray oil, can withstand 250 degrees high temperature, relatively soft.