How To Calculate Torque Extension

Torque Extension Formula:

\[ T_{wrench} = T_{bolt} \times \frac{L}{L + E} \]

Wrench Torque (T_wrench):

Unit Converter ▲

Unit Converter ▼

From:	To:

1. What is Torque Extension Calculation?

The torque extension calculation determines the adjusted torque value needed when using an extension on a torque wrench. It ensures accurate torque application to fasteners despite the added length of extensions.

2. How Does the Calculator Work?

The calculator uses the torque extension formula:

\[ T_{wrench} = T_{bolt} \times \frac{L}{L + E} \]

Where:

\( T_{wrench} \) — Torque to set on the wrench (Nm)
\( T_{bolt} \) — Desired torque at the bolt (Nm)
\( L \) — Length of the torque wrench (m)
\( E \) — Length of the extension (m)

Explanation: The formula accounts for the increased leverage created by the extension, requiring less torque setting on the wrench to achieve the desired bolt torque.

3. Importance of Torque Adjustment

Details: Proper torque adjustment is crucial for maintaining fastener integrity, preventing under-torquing (which can lead to loosening) or over-torquing (which can cause damage or failure).

4. Using the Calculator

Tips: Enter the desired bolt torque in Nm, the wrench length in meters, and the extension length in meters. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: Why is torque adjustment necessary with extensions?
A: Extensions change the effective lever arm length, altering the torque delivered to the fastener for a given wrench setting.

Q2: What happens if I don't adjust for extensions?
A: Without adjustment, you risk under-torquing the fastener, which may lead to joint failure or loosening under vibration.

Q3: Can this formula be used for any type of extension?
A: This formula works best for straight extensions. Complex extension setups or angled extensions may require different calculations.

Q4: How do I measure the lengths accurately?
A: Measure from the center of the drive square to the center of the handle for wrench length, and the full length of the extension.

Q5: Is this calculation applicable to all torque wrenches?
A: This calculation applies to click-type, beam-type, and dial-type torque wrenches. Digital torque wrenches may have built-in compensation features.