Width Of Key Given Compressive Stress In Key Calculator

Formula Used:

\[ Width\ of\ Key = \frac{\sqrt{2} \times Transmitted\ Torque\ by\ Kennedy\ Key}{Diameter\ of\ Shaft\ using\ Key \times Compressive\ Stress\ in\ Key \times Length\ of\ Key} \]

Transmitted Torque by Kennedy Key:

N·m

Diameter of Shaft using Key:

Compressive Stress in Key:

Length of Key:

Width of Key:

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1. What is the Width of Key Calculation?

The Width of Key calculation determines the appropriate width of a Kennedy key required to transmit torque between a shaft and hub while maintaining acceptable compressive stress levels in the key material.

2. How Does the Calculator Work?

The calculator uses the formula:

\[ Width\ of\ Key = \frac{\sqrt{2} \times Transmitted\ Torque\ by\ Kennedy\ Key}{Diameter\ of\ Shaft\ using\ Key \times Compressive\ Stress\ in\ Key \times Length\ of\ Key} \]

Where:

Transmitted Torque by Kennedy Key — Torque being transferred through the key (N·m)
Diameter of Shaft using Key — Shaft diameter at the key location (m)
Compressive Stress in Key — Allowable compressive stress in key material (Pa)
Length of Key — Length of the key along the shaft (m)

Explanation: This formula calculates the minimum key width required to prevent failure due to compressive stress while transmitting the specified torque.

3. Importance of Key Width Calculation

Details: Proper key width calculation ensures mechanical components can transmit required torque without failure, prevents key shearing or crushing, and maintains system reliability and safety.

4. Using the Calculator

Tips: Enter all values in consistent SI units. Ensure torque, shaft diameter, stress, and length values are positive numbers. The calculator will compute the minimum required key width.

5. Frequently Asked Questions (FAQ)

Q1: What is a Kennedy key?
A: A Kennedy key is a type of parallel key used to transmit torque between shafts and hubs, typically rectangular in cross-section.

Q2: Why is compressive stress important in key design?
A: Compressive stress determines whether the key material can withstand the crushing forces without permanent deformation or failure.

Q3: What are typical compressive stress values for key materials?
A: Values vary by material: mild steel ~70-100 MPa, alloy steel ~100-150 MPa, bronze ~50-80 MPa (consult material specifications).

Q4: How does key length affect the width calculation?
A: Longer keys distribute stress over greater area, allowing for narrower widths, while shorter keys require wider widths for the same torque transmission.

Q5: Should safety factors be applied to the result?
A: Yes, always apply appropriate safety factors based on application requirements, load conditions, and material properties.