6.3吨液压机立柱的预紧方法是什么

<=":12><=":宋体;:12><=":12> <=""> <=":12>> <=""> <=":宋体;:12><=":12><=":宋体;:12><=":12> <=""> <=":12>> <=""> <=":宋体;:12><=":12><=":宋体;:12><=":12><=":宋体;:12><=":12。<> <=""> <=":12>> <=""> <=":宋体;:12><=":12>