Bolt type tensioners:

Widely used when a nut type tensioner and bolt combination is not applicable or is not the preferred solution environmental advantages: the advantage of sufficient preload and low installation torque requires less head diameter port, and therefore requires less installation space than nut type tensioners. Compared with the bolt and nut matching, the number of parts is reduced, and the small head diameter can be put into the tight countersunk hole or space limited area.