**Bolted connection under working shear force**

As shown in Figure 1-8, this connection uses a bolt to resist the working load F through a punched hole. Assuming each bolt receives an equal working load, the shear force received by each bolt is F.

Therefore, the compressive strength condition between the bolt rod and the hole wall is:

The conditions for the shear strength of bolts are:

In the formula:

F represents the operating shear force exerted on the bolt, in Newtons;

d_{0}_{ }represents the diameter of the shear face of the bolt, which can be taken as the bolt hole diameter, in millimeters;

[τ] represents the permissible shear strength of the thread, in MPa, for steel

, where [S]_{τ} is the safety factor as per Table 1-9;

L_{min} represents the minimum height of the bolt rod squeezed by the hole wall, in millimeters.

During design, L_{min} should be greater than or equal to 1.25d; i represents the number of shear faces on the bolt rod. In Figure 1-1b, i=2, and in Figure 1-8, i=1.

The required shear stress for bolts is typically selected as 60Mpa.

The stress cross-sectional area of M1 bolt: 0.46mm^{2}

The stress cross-sectional area of M2 bolt: 2.07mm^{2}

The stress cross-sectional area of M3 bolt: 5.03mm^{2}

The stress cross-sectional area of M4 bolt: 8.78mm^{2}

The stress cross-sectional area of M5 bolt: 14.2mm^{2}

The stress cross-sectional area of M6 bolt: 20.1mm^{2}

The stress cross-sectional area of M8 bolt: 36.6mm^{2}

The stress cross-sectional area of M10 bolt: 58mm^{2}

The stress cross-sectional area of M12 bolt: 84.3mm^{2}

The stress cross-sectional area of M14 bolt: 115mm^{2}

The stress cross-sectional area of M16 bolt: 157mm^{2}

The stress cross-sectional area of M18 bolt: 192mm^{2}

The stress cross-sectional area of M20 bolt: 245mm^{2}

The stress cross-sectional area of M22 bolt: 303mm^{2}

The stress cross-sectional area of M24 bolt: 353mm^{2}

The stress cross-sectional area of M27 bolt: 459mm^{2}

The stress cross-sectional area of M30 bolt: 561mm^{2}

The stress cross-sectional area of M33 bolt: 694mm^{2}

The stress cross-sectional area of M36 bolt: 817mm^{2}

The stress cross-sectional area of M39 bolt: 976mm^{2}