Within the last generation, steel has been increasingly used for structural and ornamental purposes. Under the head of ornamental work comes the manufacture of inside and outside stairs, fire escapes, grillwork, elevator enclosures, balcony railings, fences, collar caps, vault lights, and all forms of metal-work which are decorative in character. Cold-rolled steel is always chosen for work requiring sharp corners and clear lines, such as balcony railings, doors, and grillwork, while iron is generally selected for rougher work and for jobs that do not require sharp edges. Castings are sometimes used in such cases.