Mattresses (See fig.I) shall be made of hexagonal double-twisted mild steel wire mesh. For tolerances, see Table I. Mattresses shall be supplied in various lengths, widths and heights. The tolerances of mattress’dimensions are w r ±3% in length, ±3% in idth and ±2.5cm in height acc.to elated standards. In order to strengthen the mattresses, all the edges of the structure selvedged with a wire of greater diameter. (See fig.II) Usually the mattresses having bigger length than 2meter is divided into compartments by panels (called diaphgram)positioned per 1(one) meter. If diaphgrams not requested, it should be clearly stated by client. The mesh used in mattresses strictly conforms to EN10223-3 and ASTM A975-97. Mild Steel Wire All the wires used in gabion mattresses and lacing wire have the tensile strength 2 of 38-48kg/mm (54,000-70,000psi) acc.to BS1052/80 and ASTM A641-97. (The figures above are of wire prior to manufacturing mesh).

The tolerances on diameter of zinc coated wire in Table II. The elongation at break is min.12% and test to be carried out on a sample of minimum 30cm (12 in.) long, before manufacturing the mesh. (In acc.with ASTM A370-92) Galvanisation strictly conforms to ASTM A641-97 Class III Soft Temper Coating. Zinc adherence has to be such that when thewire is wrapped around a cylindrical mandrel having 4 times the diameter of the wire, the zinc shall not flake or crack to such an extent that any flake or crack can be removed by simply rubbing with bare fingers.