Autofrettage

Autofrettage is when we make a metal pipe or cylinder stronger by squishing it really hard.

Let's say you have a regular tube made of metal. It's pretty strong, but it can still bend or break if too much pressure or stress is put on it.

So, to make it even stronger, we put it in a machine that squeezes it really, really hard. This is kind of like giving the tube a big hug, but way stronger.

When we do this, the metal gets pushed inwards and squished up against the inside of the tube. This makes the metal on the outside of the tube even stronger because it's squeezing the metal on the inside.

It's like when you squeeze a water balloon really hard - the balloon gets a lot stronger because the rubber is being pushed together tightly.

After the autofrettage process, the metal tube won't bend or break as easily because it's much stronger now.

So, basically, autofrettage is like giving a metal tube a big hug to make it stronger and able to handle more pressure!