---
title: "What is a Lego brick made of?"
description: "ABS plastic moulded to a tolerance of about ten micrometres — the tightness of the fit is the whole product. Every component, the material it uses, and the constrain"
url: https://atoneplace.net/made-of/lego-brick/
site: "At One Place"
---

# What is a Lego brick made of?

**What is a Lego brick made of?: ABS plastic moulded to a tolerance of about ten micrometres — the tightness of the fit is the whole product.**

The stud-and-tube coupling patented in 1958 is still dimensionally compatible with bricks made today, which is only possible because the moulding tolerance is around ten micrometres — a tenth of the width of a human hair. That precision is why the company has struggled to replace ABS: recycled PET prototypes were abandoned in 2023 because they did not hold the tolerance or the clutch power, and because processing them raised rather than lowered emissions. Rejected bricks are reground and remoulded rather than discarded, and the reject rate is famously in the region of eighteen per million.

## Component by component

*Every material is a choice, and the third column is the constraint that drove it.*

| Part | Material | Why that material |
| --- | --- | --- |
| standard bricks | acrylonitrile butadiene styrene (ABS) | ABS is hard, glossy, dimensionally stable and tough enough to be stepped on, and it holds colour without fading. |
| transparent parts | polycarbonate | Polycarbonate is genuinely clear and far more impact-resistant, which matters for thin windscreen and window pieces. |
| flexible parts | polypropylene or thermoplastic elastomer for hinges, tyres and hoses | A living hinge or a stretchy tyre needs a polymer that survives repeated flexing, which ABS does not. |
| plant elements | polyethylene made from sugarcane ethanol | It is chemically identical to petroleum polyethylene but from a renewable feedstock, and soft enough only for leaves and trees. |
| clutch power | the interference fit between stud and tube, held within about 10 µm | It has to be tight enough to hold a model together and loose enough for a child to pull apart, every time, for decades. |

## Other around the house objects

- [Banknote](https://atoneplace.net/made-of/banknote/) — Cotton and linen rag paper, or polymer film — never wood pulp, which is why notes survive the wash.
- [Soap](https://atoneplace.net/made-of/soap/) — Fats reacted with lye to make fatty acid salts — and most modern "beauty bars" are not soap at all.
- [Toothpaste](https://atoneplace.net/made-of/toothpaste/) — Mostly abrasive and humectant, with a detergent for foam — the active ingredient is about 0.15% fluoride.
- [Coin](https://atoneplace.net/made-of/coin/) — Base-metal alloys chosen for wear and cost — most modern "silver" coins are copper-nickel and most "copper" ones are plated steel or zinc.
- [Sunscreen](https://atoneplace.net/made-of/sunscreen/) — UV filters — mineral, chemical or both — suspended in an emulsion whose job is to hold them in an even film.
- [Credit card](https://atoneplace.net/made-of/credit-card/) — Laminated PVC sheets 0.76 mm thick, carrying a silicon chip in epoxy and a copper antenna coil.
- [Candle](https://atoneplace.net/made-of/candle/) — Wax that is really a fuel, and a braided cotton wick that acts as a pump rather than as the thing burning.
- [Lipstick](https://atoneplace.net/made-of/lipstick/) — Castor oil carrying pigment, set into a stick with waxes — the oil is the workhorse, not the colour.
- [Shampoo](https://atoneplace.net/made-of/shampoo/) — Three-quarters water, a primary detergent, a milder secondary one, salt to thicken, and silicone to make hair feel smooth.
- [Balloon](https://atoneplace.net/made-of/balloon/) — Party balloons are dipped natural rubber latex; foil balloons are metallised plastic film and are not rubber at all.
- [Deodorant](https://atoneplace.net/made-of/deodorant/) — Deodorant kills the bacteria that cause the smell; antiperspirant uses aluminium salts to plug the sweat duct. Different products.
- [Toothbrush](https://atoneplace.net/made-of/toothbrush/) — Nylon filaments stapled into a polypropylene handle with a wire — three plastics that cannot be separated for recycling.

## Common questions

### What is a Lego brick made of?

ABS plastic moulded to a tolerance of about ten micrometres — the tightness of the fit is the whole product.

### What is the standard bricks of a Lego brick made of?

Acrylonitrile butadiene styrene (ABS). ABS is hard, glossy, dimensionally stable and tough enough to be stepped on, and it holds colour without fading.

### What is the transparent parts of a Lego brick made of?

Polycarbonate. Polycarbonate is genuinely clear and far more impact-resistant, which matters for thin windscreen and window pieces.

## Related pages

- [Banknote](https://atoneplace.net/made-of/banknote/)
- [Soap](https://atoneplace.net/made-of/soap/)
- [Toothpaste](https://atoneplace.net/made-of/toothpaste/)
- [Coin](https://atoneplace.net/made-of/coin/)
- [Sunscreen](https://atoneplace.net/made-of/sunscreen/)
- [Credit card](https://atoneplace.net/made-of/credit-card/)
- [Candle](https://atoneplace.net/made-of/candle/)
- [Lipstick](https://atoneplace.net/made-of/lipstick/)
- [Pencil](https://atoneplace.net/made-of/pencil/)
- [Tennis ball](https://atoneplace.net/made-of/tennis-ball/)
- [Golf ball](https://atoneplace.net/made-of/golf-ball/)
- [Paper](https://atoneplace.net/made-of/paper/)
- [Glass](https://atoneplace.net/made-of/glass/)
- [Soccer ball](https://atoneplace.net/made-of/soccer-ball/)

## Sources

- Official vendor product documentation — At One Place (/about/)