A Plethora of Plastics
Most people know that most LEGO bricks are made of ABS, but that’s not the only plastic that LEGO uses! Historically and currently, LEGO bricks are made with a variety of materials depending on the use case. This article will explore many of them, with a brief overview of their properties and when/how they have been used.
Disclaimer: I am only a LEGO enthusiast, not a plastics specialist by any means. If anything here seems wrong or misleading, please do let me know and I will gladly correct it! Also note that within each plastic category, there is the potential for additives and colorants that may further affect how the part performs. Most of the plastics below are really names for families of hundreds of subtly different plastics. LEGO’s exact plastic formulations are trade secrets, and for good reason.
https://bricknerd.com/home/every-type-of-plastic-used-by-lego-5-20-22