The symbol for moment of a force is typically M or τ (tau).

Here's a breakdown:

* M: This is a common symbol used in many textbooks and engineering contexts.

* τ: This symbol is often used in physics and mechanics. It comes from the Greek word "torqué," which means "twist" or "turn," reflecting the turning effect of a moment.

Both symbols are used to represent the same physical quantity, and the choice often depends on context and personal preference.