Legos are the ultimate toy. You can use them to build everything from replica cities, to robots to prosthetic legs. But how many times can you use a single brick before it gives out?

Software developer Phillipe Cantin decided to find out. He built a Lego stress test machine to put the blocks through their paces.

After ten full days, of assembling and disassembling the bricks finally gave out. In the end, they were put together and taken apart 37,112 times. Here’s Cantin explaining what exactly happened:

We also know how tall you have to build a Lego structure for the bricks to break under their own weight. The Open University’s engineering department used a hydraulic ram to figure this one out. James Plafke at Geek.com explains:

In the experiment, the team used a standard 2×2 Lego brick and placed it onto a hydraulic ram. The ram pushes the brick upwards towards a metal plate with a load cell, which measures the force applied to the brick. The team set the machine to do its work automatically, so they could observe from a safe distance outside the room. After the ram was activated, the 2×2 brick managed to withstand an astonishing amount of force, finally giving in at 4,240 newtons, the equivalent of 950 pounds.

To build a structure big enough out of legos to exert that kind of force onto the blocks, you’d have to stack 375,000 other bricks on top of it.

Suffice to say, Legos are some of the sturdiest toys you can buy your kids. Forget iPads: if you want a long-lasting toy, stick with blocks.

More from Smithsonian.com:

Celebrating 80 Years of LEGO

The World’s Great Structures Built With Legos