Collection of resources to understand how grade of bolts relates to shear strength
Simple Bolt Strength
Bolt Grade Chart - This page shows the tensile strength of different bolt grades for both Imperial and Metric.
Shear Strength Analysis - Resource for calculations used here
Although no official shear strength values are calculated, the common acceptance is that the ultimate shear strength of a bolt is approximately 60% of the minimum ultimate tensile strength.
Simple Example Calculation
Comparison between a 3/4" Grade 2, Grade 5 and Grade 8 bolt.
To get the shear loading force you take the calculated shear strength and multiply it by the cross-sectional area of the fastener
Cross-Sectional Area of 3/4" Bolt
Diameter = .75" (Threads excluded bolt)
A = pi * r^2
A = 3.1416 * (0.75/2)^2
A = .4418in^2
Capability in shear = Shear strength (pounds/in^2) * Cross sectional Area (in^2)
|Bolt Grade||Minimum Tensile Strength (psi)||Shear Strength (psi)||Shear Capability (lbs)|
Situation specific analysis is required for actual meaningful data. Additional information on this can be found in the Machinery's Handbook under Working Strength of Bolts.