EngineerBenchChecking bolt shear and plate bearing
A bolted connection can be limited by the bolt or by the material around its hole. This calculator compares a simplified bolt shear capacity with a plate-bearing capacity. The lower result controls within those two checks; it does not mean that every possible connection failure has been evaluated.
Count shear planes correctly
A shear plane is an interface across which the bolt transfers load. It is not the number of plates by itself. Select whether the plane crosses the shank or threads, and use the thickness and bearing allowance of the plate being checked.
Check the surrounding connection
Edge distance, hole spacing, tear-out, net-section failure, slip, and uneven load sharing can change the connection's capacity. The model's bolt-strength approximation and user-entered plate allowance must suit the design basis. Check each relevant plate and the complete load path before selecting hardware.
Identifying the governing section
A single-shear connection transfers force across one interface through the bolt. A double-shear arrangement can transfer through two interfaces, but the plates and load path must actually create that arrangement. Doubling the selected shear-plane count without matching the physical assembly would overstate the model's capacity. Threads crossing a plane also change the effective resisting area.
Plate bearing uses projected contact area based on bolt diameter and plate thickness in this model. A thin plate can therefore govern even when the bolt's shear estimate is high. Check all relevant plates rather than assuming the thickest member represents the joint. Holes close to an edge may fail by a mechanism other than the two capacities reported here. Where several bolts are used, obtain the force at the most heavily loaded bolt from an appropriate load distribution first. Compare that force with the screening result and retain the separate checks for the plates, bolt group, and installation conditions.
Formula
Shear resistance = 0.6Fu × effective area × planes / factor. Plate bearing = allowable stress × diameter × thickness.