GD&T practice test
20 mixed questions from every GD&T lesson. Pick your standard, then work through them.
Which is the secondary datum?
What this test covers
Each question comes from one of these lessons. If a topic trips you up, go back to that lesson for more practice.
- GD&T symbols: The 14 geometric characteristics, what they look like, and which need a datum.
- Reading a feature control frame: Characteristic, tolerance zone, modifier and datums, read left to right.
- MMC, LMC and bonus tolerance: Maximum and least material condition, and how much extra position tolerance a part gets.
- Work out bonus tolerance: MMC size, bonus and total position tolerance, typed instead of picked.
Explained in our own words and checked against several GD&T references. For the full rules, see ASME Y14.5-2018 and ISO 1101:2017.