### Minimum Thread Engagement Equation and Calculator ISO

**Fastener and Thread Design Menu**

ISO Hardware Data

ANSI Hardware Data

**Mechanics / Strength of Materials Menu**

The screw should fail before the thread strips. For this, it is necessary the shear area of the threaded feature be at least 2 times the tensile area. (Assuming the threaded feature is of the identical material).

Where:

L_{e} = Minimum Thread Engagement Length

A_{t }= Tensile Stress Area

D = Major
Diameter of fastener (screw)

p = 1 / Number of threads per inch
(n)

Open Minimum ISO Thread Engagement Calculator

**Threaded Hole / Fastener Ratio: **

Open - ISO Thread / Fastener Ratio and Length Calculator

This assumes that the male and female thread materials have the same strength. If the Female Material strength is lower i.e. J as calculated below is greater than 1 then the length of engagement must be increased to prevent the female thread stripping

Where:

J = Thread Engagement Ratio

If the value of J is greater than 1 then the length of engagement
must be increased to at least

Where:

l_{e} = Thread Engagement Length

Related

- Fastener Relation Between Torque, Thread Pitch and Clamping Force Formula and Calculator
- Fastener Relation Between Bolt Torque and Clamping Force Formula and Calculator per. JIS B 1083
- Metric M Series Thread Stress and Shear Areas
- ISO Stress Area Equation and Calculator - Proof load values are given in BS EN 20898-2:
- BS EN 20898-2 Proof load values - Coarse thread
- Minimum Length of Thread Engagement Formula and Calculations Per FED-STD-H28/2B
- Torque Design Guidelines
- Typical Elongation Chart for Common Bolting Materials
- Loading Capacities of Ordinary Bolts per. BS449: Part 2 Bolt Grade 4.6
- Loading Capacities of Ordinary Bolts per. BS449: Part 2 Bolt Grade 6.8
- Loading Capacities of Ordinary Bolts per. BS449: Part 2 Bolt Grade 8.8
- Loading Capacities of Ordinary Bolts per. BS449: Part 2 Bolt Grade 10.9
- Loading Capacities of Ordinary Bolts per. BS449: Part 2 Bolt Grade 12.9
- Torque Wrench Adapter Reduced Arm Calculation
- Torque Wrench Adapter Extended Calculation