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Factor of Safety
Factor of Safety is a core engineering term. Definition, usage notes, and a practical example.
Definition
Factor of safety is the ratio of capacity to expected load.
Why it matters
It covers uncertainty, tolerance, material scatter, and service conditions.
How it is used
In a design check, first define the relevant load, dimension, material, or flow condition. Then interpret this term by its role in the formula and compare it with limits.
FoS = Capacity / Demand
Example
If capacity is 3000 N and load is 1000 N, the factor of safety is 3.
Related calculators and resources
Formulas
FoS = Capacity / Demand