This International Standard specifies the requirements of glass-fibre wound, polyester or polyesterimide varnish-treated, bare or grade 2 enamelled rectangular copper winding wire, temperature index 180. The temperature index of the glass-fibre wound varnish-treated wire is dependent upon the type of varnish used. The varnish applied to the glass-fibre is based upon polyester or polyesterimide resin and shall have a minimum temperature index of 180. The method of test is to be agreed between purchaser and supplier.