GD&T Tolerances & Fits in Engineering Drawings 4

Question 1

A dimension shown as 62.50/62.45 on a drawing uses which tolerance expression method?

Accepted Answer

Limit dimensioning

Answer

Limit dimensioning directly states the maximum and minimum acceptable sizes without referencing a nominal value or deviation.

Question 2

If a shaft has a tolerance of 0.025 mm and the mating hole has a tolerance of 0.030 mm, what is the assembly tolerance?

Accepted Answer

0.055 mm

Answer

Assembly tolerance equals the sum of both component tolerances: 0.025 + 0.030 = 0.055 mm.

Question 3

In the shaft-basis fit system, which letter designates the reference shaft with zero fundamental deviation?

Accepted Answer

h

Answer

In the shaft-basis system, 'h' designates the reference shaft whose upper deviation is zero.

Question 4

Which statement correctly describes 'least material condition' (LMC) for an external feature (shaft)?

Accepted Answer

The shaft is at minimum diameter

Answer

LMC for an external feature (shaft) occurs at its smallest permissible diameter, where the least material is present.

Question 5

A clearance fit specified as H8/f7 compared to H7/f6 would generally have:

Accepted Answer

Larger tolerances and more clearance variation

Answer

Higher IT grade numbers (8 vs 7, 7 vs 6) mean wider tolerance zones, resulting in more variation in clearance across the assembly.

(GD&T) Geometric Dimensioning and Tolerancing Certification Practice Test