A hex important (or else referred to as an Allen crucial) is necessary to suit these fasteners. Conforming to ISO 4762 or DIN 912, the Make contact with surfaces of this screw or bolt are shielded from external damage. This variant is provided absolutely threaded despite duration of screw. Microsoft https://andersonzdujy.blogolenta.com/27418281/5-essential-elements-for-masonry-screws