Grip Range: All fasteners, rivets, bolts, studs, screws, and concrete anchors are measured in terms of their grip range. The grip range is the total thickness of the material to be fastened under the head plus the necessary thread engagement, or set, as in the case of concrete anchors and rivets.
Grades: The relative strengths between bolts, nuts, and some screws and rods are 2, 5, 8, A-307, A-325, A-490, B-7, and B-16. In metrics, they are 8.8, 9.8,10.9,12.9, and are marked accordingly.
Threads per inch or pitch: Threading is measured in threads per inch or pitch, or millimeters as in the case of metrics.