---
title: "Torque Calculation"
slug: "torque-calculation"
tags: ["FCM"]
updated: 2026-10-27T23:12:05Z
published: 2026-10-27T23:12:05Z
canonical: "ims-handbook.cenosco.com/torque-calculation"
---

> ## Documentation Index
> Fetch the complete documentation index at: https://ims-handbook.cenosco.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Torque Calculation

For imperial: ${\Large T = \frac{S_{b} \times A \times D\times K}{12} }$

For Metric: ${\Large T = \frac{S_{b} \times A \times D\times K}{1000} }$

Torque calculations:

| Symbol | Name | UoM | Source |
| --- | --- | --- | --- |
| T | Torque | ft-lbs | Calculated. |
| Sb | Target Bolt Stress | psi | LOOKUP (based on Flange SIZE and CLASS RATING). If inputs missing then 70% of the Bolt Yield Stress is suggested. See [Target Bolt Stress Lookup](/v414/docs/target-bolt-stress-lookup). |
| A | Bolt tensile stress area | in2 | Calculated. |
| D | Bolt nominal diameter (stud size) | in | LOOKUP (based on Flange SIZE and CLASS RATING). See [Stud Size Lookup](/v414/docs/stud-size-lookup). |
| K | Nut factor | dimensionless | User entered value. (Typically a value of 0.17 is used for uncoated studs properly lubricated with nickel-based anti-seize, and 0.12 for Teflon-coated studs is used.) |

Example:

Calculating the torque required for a bolt using both imperial and metric formulas.

Imperial Calculation if:

- Target Bolt Stress (Sb): 73,505 psi
- Bolt Tensile Stress Area (A): 0.969 in²
- Stud Size (D): 1.25 in
- Nut Factor (K): 0.12

${\Large T = \frac{73\,505 \times 0.969 \times 1.25 \times 0.12}{12} \approx 890.4 \, \text{lbf-ft} }$

Metric calculation if:

- Target Bolt Stress (Sb): 560.8 MPa
- Bolt Tensile Stress Area (A): 6.25 cm²
- Stud Size (D): 31.75 mm
- Nut Factor (K): 0.12

${\Large T = \frac{560.8 \times 6.25 \times 31.75 \times 0.12}{1000}\approx 1207Nm}$