friction grip bolt meaning in English

摩擦夹紧螺栓

Specification for the use of high strength friction grip bolts in structural steelwork - metric series - general grade
结构钢制构件高强度摩擦紧固螺栓应用规范,米制系列.第1部分:普通螺拴
Specification for the use of high strength friction grip bolts in structural steelwork - metric series - higher grade parallel shank
结构钢制构件中高强度摩擦紧固螺栓应用规范,米制系列.第2部分:高级螺拴