JB机械标准 JB 8112-1999 一般起重用锻造卸扣D形卸扣和弓形卸扣 JB 8112-1999.Forged shackles for general lifting purposes—Dee shackles and bow shackles. 1范围 JB 8112... 05月23日JB 8112 阅读全文