1. What is Torque on a Bolt?

Torque on a bolt is the rotational force applied to tighten the bolt. Proper torque ensures the bolt is tight enough to withstand operational forces without being over-tightened, which could damage the bolt or the materials being fastened.

2. How Does the Calculator Work?

The calculator uses the torque equation:

Where:

• \( K \) — Friction factor (unitless, typically 0.15-0.25 for dry steel)
• \( F \) — Axial force applied (newtons)
• \( d \) — Nominal bolt diameter (meters)

Explanation: The equation accounts for the relationship between applied force, bolt size, and friction to determine the required torque.

3. Importance of Proper Torque

Details: Correct torque is crucial for bolt performance. Under-torquing can lead to joint failure, while over-torquing can strip threads or break bolts.

4. Using the Calculator

Tips: Enter friction factor (typically provided by manufacturer), force in newtons, and bolt diameter in meters. All values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What's a typical friction factor (K) value?
A: For dry steel, K is typically 0.15-0.25. Lubricated bolts may have K values as low as 0.10.

Q2: How do I convert pounds to newtons?
A: Multiply pounds by 4.448 to get newtons (1 lb = 4.448 N).

Q3: Should I use major or minor diameter?
A: Use the nominal (major) diameter of the bolt for most calculations.

Q4: Why does friction affect torque?
A: Friction between threads and under the bolt head means only part of the applied torque actually tensions the bolt.

Q5: How accurate is this calculation?
A: This provides an estimate. Actual torque requirements may vary based on surface finish, lubrication, and other factors.