Bolt shearing

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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)

r= dia/2

A = pi * r^2

A = 3.1416 * (0.75/2)^2

A = .4418in^2

Shear Capability

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)
2 74,000 44,400 78,000
5 120,000 72,000 127,000
8 150,000 90,000 159,000

Advanced Analysis

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.

Wanted: If anyone has access to a Machinery's Handbook and can provide further information that would be great!