1. What is Factor of Safety?

The Factor of Safety (FOS) is a design criterion that represents how much stronger a system is than it needs to be for an intended load. It's the ratio of the ultimate strength of a material to the working stress.

2. How Does the Calculator Work?

The calculator uses the Factor of Safety formula:

Where:

• Ultimate Strength — Maximum stress a material can withstand (Pa)
• Working Stress — Actual stress the material will experience in use (Pa)

Explanation: The equation calculates how many times stronger the material is compared to what's required for normal operation.

3. Importance of Factor of Safety

Details: Proper FOS ensures structural integrity, accounts for material variability, unexpected loads, and potential degradation over time. Different industries have standard FOS requirements.

4. Using the Calculator

Tips: Enter both ultimate strength and working stress in Pascals (Pa). Both values must be positive numbers.

5. Frequently Asked Questions (FAQ)

Q1: What is a good Factor of Safety value?
A: Typical values range from 1.2 to 4.0 depending on the application. Critical components often use higher values.

Q2: Can FOS be less than 1?
A: Yes, but this indicates failure is expected under working conditions. Some temporary structures may use FOS < 1 with special considerations.

Q3: How does FOS differ from safety margin?
A: Safety margin is usually expressed as (FOS - 1) × 100%. FOS of 2 equals 100% safety margin.

Q4: Why use different FOS for different materials?
A: Materials have different variability in properties. Brittle materials typically require higher FOS than ductile ones.

Q5: How does FOS affect design?
A: Higher FOS means more material is required, increasing cost and weight. Engineers balance safety with efficiency.