12.9级凹端无头内六角螺丝钉机米紧定顶丝M3M4M5M6M8M10M12M16M20
12.9级外六角螺丝螺栓高强度全牙加长5M6M8M10M12M14M16M18M20M22
316防松尼龙螺母防滑牙自锁锁紧/304不锈钢螺帽3M4M5细牙美制反牙
厂家直销 M1.6-M48系列 全牙半牙规格齐全
304不锈钢3M4M5M6M8内六角螺丝钉螺栓*10/12/14/16/18/20/22/30/