1. What is Crushing Strength of Key Calculator?

Definition: This calculator determines the tangential force that a key can withstand before crushing occurs, based on key dimensions and material properties.

Purpose: It helps mechanical engineers and designers ensure keys in shaft assemblies have sufficient strength to transmit torque without failure.

2. How Does the Calculator Work?

The calculator uses the formula:

Where:

• \( F \) — Tangential force (Newtons)
• \( l \) — Length of key (meters)
• \( t \) — Thickness of key (meters)
• \( f_c \) — Crushing stress in key (Pascals)

Explanation: The formula calculates the force that would cause crushing failure by considering the key's dimensions and material strength.

3. Importance of Key Strength Calculation

Details: Proper key strength calculation ensures reliable power transmission, prevents mechanical failures, and maintains safety in rotating machinery.

4. Using the Calculator

Tips: Enter the key length, thickness (typically 1/6 of shaft diameter), and material crushing stress. All values must be > 0. Results include ±5% tolerance.

5. Frequently Asked Questions (FAQ)

Q1: Why is thickness divided by 2 in the formula?
A: The force acts on half the key thickness because the crushing stress is distributed across the contact area.

Q2: What's a typical crushing stress for key materials?
A: For mild steel keys, crushing stress is typically about twice the permissible shear stress (≈100-150 MPa).

Q3: How does key length affect the result?
A: Longer keys can withstand greater forces as the load is distributed over a larger area.

Q4: What does the ±5% tolerance represent?
A: It accounts for manufacturing variations, material inconsistencies, and safety factors in practical applications.

Q5: When would I need to calculate key crushing strength?
A: Whenever designing or analyzing shaft-key assemblies for power transmission systems like gears, pulleys, or couplings.

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