Choosing yours
More than any various other tool, a ratchet can last you an eternity. Quality ratchets can be serviced inexpensively therefore should never degrade. Sockets happen to be interchangeable because they are all standard. Choose the very best ratchet you can afford, even if you get inexpensive sockets to start out with.

Socket release
Sockets will be held onto the ratchet using a small spring-loaded ball privately of the square travel. After applying a lot of power, I’ve sometimes found sockets get stuck on the travel and the only way to have them off is usually to hammer the ratchet on the floor or even grip it in a vice. Good quality ratchets include a button on the back which efficiently pushes off the socket while you are ready to release it.

1/4 inch – Used for smaller sockets and precision work. Useful for dismantling individual parts on the bench.
3/8 inch – The middle sized, and for me, most useful size for basic use on an automobile. A 3/8″ drive can travel sockets of all sizes. It is big enough to apply quite a lot of force, but certainly not too big to fit into tight spaces
1/2 inch – 1/2″ sockets are usually applied for nuts and bolts from around 10mm and up. A 1/2″ drive socket can apply enough drive to undo all nuts on an automobile.
Additionally, there are 3/4″ and 1″ ratchets but these are used on trucks, tanks and industrial machinery.
Tooth count
Ratchets Wheel Inside a ratchet there is a toothed wheel which lets it freely rotate as you tighten the nut. Each click you hear is a tooth passing the ratchet. The more tooth there are, the significantly less movement is needed on the return stroke. A ratchet with 75 teeth will work considerably faster than a 32-tooth ratchet. Making large tooth-counts requires quality engineering and developing, so as a general guide the better top quality tools will have an increased tooth count.

Drive sizes
socket-drive-sizes
All ratchets accept sockets by using a square drive and mostly there are 3 sizes of drive. All around the globe these sizes are given in inches – even though the sockets are metric.