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直径12毫米的倒楔式锚杆,按部颁标准拉力强度不得小于4吨。过去生产这种规格的锚杆,是直接用相同规格的圆钢截成
12 mm in diameter inverted wedge anchor, according to the ministerial standard tensile strength of not less than 4 tons. The past production of such specifications bolt is directly cut with the same specifications of the round bar