Galvanized spiral mechanical properties of yield strength (N/mm2) ≥ 205 Tensile strength ≥ 520 extends rate (%) ≥ 40 Hardness HB ≤ 187 HV HRB ≤ 90 ≤ 200 density of 7.93 g · cm-3 specific heat c (20 ℃ ) 0.502 J · (g · C) -1 thermal conductivity λ / W (m ° C) -1 (following temperature / ° C) 20 100 500 12.1 16.3 21.4 linear expansion coefficient α / (10-6 / ° C) ( in the following temperatures / ° C) 20 to 100 20 to 200 20 300 20 ~~ 400 16.0 16.8 17.5 18.1 resistivity of 0.73 Ω · mm2 · m-1 melting point of 1398 to 1420 ℃ Ding Shun Tianjin Steel Pipe Sales Co., Ltd. since its inception, has been adhere to the "quality of survival, to product development, reputation and security cooperation, in order to win customer service" approach to business, under the guidance of the operating principles, the company perennial way to the distributor's sales and distribution: Tianjin Seamless Steel Factory, Chengdu, Panzhihua Iron and Steel, Baotou Steel, Steel, Baoshan Iron and Steel, Anshan Iron and Steel and other major steel seamless pipe, stainless steel seamless pipe and alloy pipe, the company has a modern large-scale open-air library and indoor library with the cash of more than 3,000 tons . http://tjdsgg.cn