My mum and I share a love of LEGO, but she is a huge collector of LEGO with easily 100kg spread across the garage, her room and my nan's garage.

When she gets time to sit down and sort through her immense collection, she's always more excited when she comes across a brick which has "pat pending" written on it. She has spent hours searching for pat pending bricks to complete an entire retro set out of this brick type.

I want to know why two otherwise identical bricks can be so different in importance - a standard brick vs a pat pending one - to an avid collector of LEGO, when to me, they are otherwise the same and I'd probably mix them up by accident.

  • I have several pat pending bricks from the 60's. As my father worked for BX plastics in Essex at the time I know they are genuine. Commented Jul 14, 2020 at 15:11

3 Answers 3


As I understand it, "Pat. Pend." bricks were made in the 1960's.

Later around 1970 they removed "Pat. Pend." by carving it out of the molds, so there is a lump in place of it. These are sometimes called "Pat. Pend. removed". Those ran until 1976-ish?

I don't think any of these bricks are much more valuable than the others. Old generic bricks aren't generally worth very much. If one wanted to have genuine 1970's pieces for personal reasons, I guess they might look for these markings.

I don't think all pieces had those markings though.


They are rarer because fewer exists, they were made a long time ago, and LEGO has procuded many more elements since.

They are treasured by some because some collectors value having accurate bricks in their old sets, because they get that bit more authentic. I only care when there's a more easily visible difference like a groove on 2x2 tiles, or open/closed studs on round 1x1 bricks (and it that case I care more about using the right ones where visible). In some cases this can mean the prices for the old pieces are a little higher, but the condition of such old elements often detract from the price, so don't expect to make a lot of money selling those parts of your mom's collection.


If you're selling an old set, you naturally want it to be made of old bricks. How would you like to buy a 1960's set, paying a vintage price, only to find that its bricks are 2010 vintage? Such a set must be comprised of bricks of its era. That why pat-pend bricks are important.

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