Bolt Stress MIL-HDBK-5

Calculates the allowable pre-load after a user input shear load or the allowable shear load after a user input pre-load for coarse and fine thread bolts from 1/4' diameter to 1' diameter. Allowable loads are plotted by diameter and thread count. This spreadsheet uses an interaction equation from MIL-HDBK-5. All equations are worked by hand and documented. I use this every day for quickly sizing bolts because of how easy it is to use and understand.  

Calculation Reference

Bolted Joint

Bolt Strength

MIL-HDBK-5

The Bolt Stress MIL-HDBK-5 is a handbook that provides guidelines for calculating the allowable pre-load or shear load for coarse and fine thread bolts of various diameters ranging from 1/4' to 1'. It follows specific methods and formulas outlined in the handbook to ensure the safe and reliable design of bolted connections.

To use the Bolt Stress MIL-HDBK-5, you typically need to input the following information:

1. Bolt Diameter: Specify the diameter of the bolt being used for the connection.

2. Thread Type: Specify whether the bolt has a coarse thread or a fine thread. The thread type affects the calculation of thread engagement and effective stress area.

3. Shear Load or Pre-load: Depending on the specific calculation you want to perform, input either the shear load applied to the bolt or the desired pre-load (also known as the axial tension) in the bolt.

The Bolt Stress MIL-HDBK-5 uses established equations and methods to determine the allowable pre-load or shear load based on the provided input. It considers factors such as bolt material properties, thread engagement, fastener grade, and other relevant factors.

The handbook typically provides tables or charts that present the calculated values for allowable pre-load or shear load based on the given input parameters. These values are determined by considering factors such as material strength, thread engagement, and safety margins.

It is important to note that the Bolt Stress MIL-HDBK-5 is a reference guide, and its usage should be accompanied by an understanding of the underlying principles and assumptions. It is recommended to consult the specific sections and tables relevant to your bolt diameter and thread type within the handbook to obtain accurate and up-to-date information.

Additionally, it is crucial to ensure that the calculated allowable pre-load or shear load is within the acceptable limits and meets the requirements of the specific application, design codes, and standards. Consulting with a qualified engineer or utilizing software specifically designed for bolted connection analysis is advisable to ensure the accuracy and reliability of the calculations.