# Bolt shearing

## Contents

# Overview

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!