PM12 PM24 Underground Mining Expandable Friction Swellex Hydra Bolt with SGS testing

Expandable Friction Bolt: Expandable Friction Bolt is made by high strength welded tube folded itself and welded to seal at both end of bolt. Expandable Friction Bolt is also named Swellex , Hydra bolt, Inflatable bolt.   Product Parameters: Item  No. Bolt Diameter Steel thickness Original Tube Diameter Bushing Head Diameter Upper Bushing Diameter   Min Breaking Load Expansion Pressure Minimum Elongation ATEF120 28mm 2mm 41mm 30/36mm 28mm 110KN 300bar 10% ATEF160 38mm 2mm 54mm 41/48mm 38mm 150KN 240bar 10% ATEF240 38mm 3mm 54mm 41/48mm 38mm 230KN 300bar 10%   How To Work: When the bolt is used in the hole, the bush with a hole is connected with a chuck of a high-pressure water pump. Start the pump and inject the water into tube, the folded wall of bolt is forced to expand. When the pump reaches a standard pressure, the wall of bolt holds onto the strata and creates a big frict…