Thread Engagement Length Calculator

Formula

The formula to calculate the minimum thread engagement length (Le) is:

\[ Le = \frac{2 \times At}{0.5 \times \pi \times (D - 0.64952 \times p)} \]

Where:

\(Le\) is the minimum thread engagement length (in)
\(At\) is the tensile stress area (in^2)
\(D\) is the diameter of the screw (in)
\(p\) is the thread pitch (1/number of threads per inch)

What is a Thread Engagement Length?

A thread engagement length is considered the minimum viable length of thread that needs to be in contact with the opposite thread wall to handle a certain amount of stress. This ensures the connection can withstand the applied forces without failing.

Example Calculation

Let's assume the following values:

Tensile Stress Area (At) = 0.1 in^2
Diameter of the Screw (D) = 0.5 in
Thread Pitch (p) = 0.1

Using the formula:

\[ Le = \frac{2 \times 0.1}{0.5 \times \pi \times (0.5 - 0.64952 \times 0.1)} \approx 0.2927 \, \text{in} \]

The Minimum Thread Engagement Length is approximately 0.2927 inches.