Q235 steel anchor bolts anchor bolts for general use, it is light round. Rebar (Q345) strength, do not light round threaded nut easily. For light round bolt, the burial depth for 25 times the diameter, and then do a 120mm length of about 90 degrees hook. Bolt tensile capacity is round itself tensile strength, and tensile strength multiplied by the cross-sectional area equal to the size of the design value (140MPa) is to allow the tension strength of the design. Q235 steel anchor bolts for general use, is light round. Currently not seen with the case of the thread, but if force might also be needed. Rebar (Q345) strength, do not light round threaded nut easily. For light round bolt, the burial depth for 25 times the diameter, and then do a 120mm length of about 90 degrees hook. If large bolt diameter (eg 45mm) depth is too deep, it can bolt ends welded square plates, which make a bulk of it (but also have certain requirements). Depth and the hook is to ensure that the foundation bolts and friction, and will not pull out the bolt damage occurred. Therefore, the bolt tensile capacity is round itself tensile strength, and tensile strength multiplied by the cross-sectional area equal to the size of the design value (140MPa) is to allow the tension strength of the design.