Tensile capacity of anchor bolts is tensile capacity of the bar itself, the size is equal to the cross-sectional area multiplied by the allowable stress (Q235B:140MPa, 16Mn or Q345:170MPA) is to design the permissible tensile force.
Q235 steel used for bolt, which is round. Rebar (Q345) strength, nut threads did not round easy. For light anchor bolts, and depth is generally 25 times times the diameter, and then do a 120mm length of 90-degree hooked. If the bolt diameter is large (such as 45mm) buried deeper and deeper, at end of bolt welding plate, that is, do a big head can (but also have certain requirements). Depth and a hook is to ensure that the bolt and the basis of friction, so that the bolt pullout.