Quality control — tolerances, gauging, inspection

What you'll learn

1. 1

   Imagine you're making 1,000 bolts. They must all be the same size — but tiny differences happen. Tolerances tell you the 'wiggle room' that's still OK.

2. 2

   A bolt must be 10.0 mm with a tolerance of ±0.2 mm. What's the smallest size that passes?

3. 3

   Drag the gauge to check if this bolt (9.7 mm) passes — the tolerance is 10.0 mm ± 0.2 mm.

4. 4

   Let's check if a shaft diameter of 24.95 mm passes with tolerance 25.00 mm ± 0.05 mm.

5. 5

   A hole must be 12.00 mm ± 0.10 mm. Which of these measurements would FAIL inspection?

6. 6

   What does a 'go/no-go' gauge do?

7. 7

   Use the gauge to check this part: target 50.0 mm, tolerance ±0.5 mm. The part is 49.3 mm — pass or fail?