A multi jackbolt tensioner including tamper resistant jackbolts

摘要

A multi jackbolt tensioner (10) includes a jackbolt tensioner body (12) and jackbolts (22). The jackbolt tensioner body (12) includes a plurality of holes (14) spaced uniformly from a longitudinal central axis (16) at spaced apart locations about an outer periphery thereof, the holes (14) having sidewalls formed with body threads (18). The jackbolts (22) each include jackbolt threads (24) to threadedly engage the body threads (18) in one of the holes (14) in the jackbolt tensioner body (12). The jackbolts (22) further include torque receiving surfaces (32,42,50,60) all disposed about the periphery of each jackbolt (22) in a mutually non-parallel relation to prevent the unauthorized application of torque or stress removal.