Should I replace my old gas spring with an identical model, or a more powerful version?

You should always replace an old gas spring with an identical gas spring – a gas spring with the same unique reference and force. The reason for this is that the construction where the gas spring is installed is configured for this force (the weight pushed by the gas spring). It is possible to adapt the force, but Hinscha recommends that you do not use a gas spring whose force is significantly different (e.g. differs by more than 30%). This is because a heavier load on the hinge or other parts of the construction can damage it.

However, if the original gas spring is no longer available, you cannot do any damage by buying a gas spring with identical dimensions, but a very slight difference in force. The force of a gas spring is usually expressed in Newton, and 10 Newton is equivalent to approximately 1 kg. So, for example, a gas spring of 80 N or 90 N can generally be replaced by a 100N gas spring with no problems at all, or a 650N gas spring with a 700N gas spring. However, if your 650 N gas spring was effective where it was installed, it is not a good idea to replace it with a 1,000N gas spring.