I am going to set up a swing frame on the terrace for both a hanging chair and a small baby swing. The hanging chair, which is for adults, I estimate can take 150 kg and the baby swing only 10 kg. What dimension of the 3-meter-long beam do I need for it to withstand at least 160 kg? 45x 170?
45x170 works well as long as it is not burdened by any other load.
Not if the beam is only supposed to support the swings.