🔍 Key Concepts

• Difference between whole depth and working depth of gear teeth • How working depth relates to the addendum circles of two mating gears • Which arrows in the illustration measure between parts of both gears versus just a single tooth

💭 Think About

• Look at where the two gears actually mesh and ask yourself: which dimension shows how deep one tooth enters the space of the mating gear during operation? • Identify which arrows measure from the pitch circle to tooth tip or root (single-gear dimensions), and which arrow measures between the addendum circles of the two meshing gears. • Consider that working depth is the sum of the addendums of the two gears; which labeled distance best matches that idea in the figure?

✅ Before You Answer

• Be sure you can point to the two addendum circles (outer tooth-tip circles) for each gear before choosing. • Confirm that the letter you pick is NOT just the single tooth whole depth (from tooth tip to its own root circle). • Check that the correct dimension involves the engagement of both gears together, not just one isolated gear tooth.