Starting by a torus, I'd like to make the shape of a chain link without touching the torus minor radius. Saying this I'm excluding the use of scale in object/edit mode, as it will change the minor radius and deform the continuity.
Is there a way to move all 4 link edges symmetrically?
For an End Chain Link (on the right in the picture) it is enough to start with a torus, split it vertically and re-bridge it later. The Common Chain Link (left in the picture) does have slightly squeezed/angled sides, which I'd prefer to deform/edit once for the one corner and all the others shall just follow the editing, i.e. remain symmetrical along the X-Y-Z axes.