Minimum Length of Engagement (Le)

Determine the minimum thread depth required to prevent the tapped hole from stripping before the bolt yields.

Inputs / Parameters

Design Principle:
To ensure structural integrity in a bolted joint, the fastener must break in purely tensile stress before the female threads strip out in shear, providing visible warning of overload.

Le ≈ R × (2 × At) / (π × D × 0.5)
Calculation assumes 50% shear strength relation (Tresca criterion) and an approximation of thread shear area. Ideal for standard UN profile threads.

Results

Minimum Required Engagement Length (Le)
0.000"
Diameter Ratio
1.0 D
Bolt Tensile Area
0.000 sq in
Material Strength Ratio (Bolt / Hole)
1.00