OSBORN METALS SA Square Tubes with big wall thickness OSBORN METALS SA offers a catalog of square tubes for agricultural machining or similar applications. Several sets of telescopic tubes, sliding in one another are available in stock in our workshops or at some distributors. Usual ranges: Section Outside Tolérance Inside Tolérance External Radii Internal radii * Other sizes, up to 135mm square are manufactured on request. Example: range of squares from 40 - 55 - 70 - 85