They are made from iron deep-drawing plates, formed by cold forging. Materials of thickness from 1 to 1.3 mm (19 - 18 gauge) are processed.

Materials of 1.5 mm (16 gauge) or wider are warm-worked by forging in furnace.

Hard couplings are riveted, flame welded or overlapped and worked in (with more difficult products).

Rivets are spaced with natural leather and mats.

Movable couplings are a system of grooves and rivets, springiness of couplings is provided by the system of straps.

Parts of the set are coupled with the system of straps, splits and pawls.

Inner parts are on request upholstered with natural materials.