For code-type locks that don't need a key, there are 'free dial' systems where you can set any number you like, and fixed types where the number is set in advance.

She tried again to fix the earring into her ear.

A famous Japanese poet does not approve of any fixed doctrine in haiku.

Make sure that the device is attached firmly to the ceiling.

You had better fix the bookcase to the wall.

The hierarchy of rank has long been fixed.

The device is attached fast to the ceiling.

This table is shaky. Make it stay firm.

To make a web, it starts by making a frame of this silk and fastening it to hard objects, such as trees or fences.

Astronauts are weightless and can sleep in any orientation. However, they have to attach themselves so they don't float around and bump into something.

First, you need to fix it firmly in place.

Try to think outside the box.