Whether it is a horizontal or vertical model, the principle of operation is basically the same. Hydraulic pressure and a splitting wedge are essential. In most lying models, the hydraulics move the carriage on which you place the piece of wood forward. The wood is pressed against the splitting wedge and split. On upright models, it is the splitting wedge that moves hydraulically up and down.

There is no general answer to this question. It depends entirely on the type of wood and the length of the material to be split. Simple models have a splitting pressure of four to eight tons.
If you only want to split blocks of wood with a relatively short length into logs for your fireplace, a pressure of six tons is absolutely sufficient. For hardwoods it may be a little more.
Devices with more than twelve tons are real powerhouses that are suitable for professional forestry work.

Generally, horizontal log splitters require less oil - in some cases only 2.4 litres. In the standing version, up to five litres of hydraulic oil must be added to the tank.
The exact quantity varies from model to model. Exact litre specifications as well as information on the specification of the suitable oil can be found in the manufacturer's specifications of the respective device.

Two-handed operation is an absolute must. This means that you have to operate one button or lever with each hand. This sounds awkward at first, but it is actually for safety. This guarantees that you don't have a free hand with which you can accidentally reach into the device and bruise yourself.
Another indispensable feature is an electrical start-up safety device. This prevents the machine from starting unintentionally when the current flows again after an interruption in the circuit.
Other important safety features are the following:
Safety emergency switch: when pressed, the log splitter stops immediately.
Hose covers: These prevent oil from leaking from the hydraulic lines.
Overload valve: It reduces the pressure when the splitting wedge hits material that is too hard, thus protecting the motor from damage.