My vintage LEGO sets (circa 1980) are difficult to unbuild. Some pieces are prone to break. Did the plastic recipe change with time or are the bricks simply degrading?

  • 1
    Forgot to ask, you didn't glue them, did you?
    – Joubarc
    Oct 26, 2011 at 18:15
  • I don't have an answer, but the feel of Llegos today (2014) is not the same as it was when I was a kid (1970s). The bricks today "slide together" (dynamic friction) while my old bricks "chattered" (stick and slip static friction) and clicked when you pressed them together. My feeling is that the newer bricks have more of a flexible plastic, but perhaps it is just the surface is smoother due to better machining tolerances. Jul 7, 2014 at 6:28

1 Answer 1


The LEGO company switched to ABS in 1963, bricks produced before that have a markedly different quality.

However, if your sets are from around 1980, they should use ABS already and there should be no reason that the plastic is different.

Other possible explanations would be bad storage conditions (too warm, direct sunlight, maybe), or the fat that the set may have only been built once. Indeed, ABS bricks reach their optimal clutch power after having been assembled/disassembled about 8 to 10 times, so if you just built the set once and let it be (for display for example), then the bricks are in fact still too new and clutch together too tighly.

  • 11
    Gah, you mean I need to pull all my Star Wars LEGO models apart and rebuild them a number of times? Noooo! Oct 26, 2011 at 15:10
  • Thanks for your answer! My lego blocks were thoroughly used. It feels like they lost any elasticity they had. ie I'm breaking my nails on them. Newer lego sets are soft and gentle and are undone pleasantly...
    – jfyelle
    Oct 26, 2011 at 21:32
  • 4
    ABS are not necessarily the same formula. Many additives have come on the market in particular to combat UV and cracking.
    – Erik Olson
    Oct 28, 2011 at 9:36
  • 2
    Actually I was just checking my CA bricks and they are softer than my old ABS parts still.
    – Erik Olson
    Oct 28, 2011 at 9:40

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.