The bolt rod is made of a 18G2A or R55 ø30 x 6.3 mm steel tube and plain AP 600 or 34GS steel bar of ø18.3 mm. KE-4W/M20 shell fixes the bolt in the hole during the injection.
The top part of the ø30 x 6.3 mm tube has an internal M20 thread for coupling with the M20 threaded bar and 4 ø6 mm holes for the adhesive injection grout. The bottom part of the tube has a M30x2 thread, whilst in the mid-section there is a stopping collar to work with the seal. The seal is a rubber tube that expands after applying the tube and M30x2 nut.