If a swivel caster has a max load weight of 50kg does that mean 4 of them would have a max load weight of 200kg? or is it still 50kg?
Strictly speaking it's 100kg because on an uneven floor all the weight could be on a diagonal. This is the safe approach. If you use 3 then 150kg because they will all bear no matter what (old fashioned milling stools had 3 legs because the dairy floors back in the day were less than perfect).