The dimensional tolerance refers to the tolerances relating to the diameter of the drilled hole. If a tolerance is not shown on the drawing then generally the expected tolerance is±0.2mm.
An example for a dia 10mm with a H７ tolerance, as long as the drilled hole is more than 10mm and less than 10.015mm in diameter then it is acceptable. Note that a capital H means the positive tolerance of a hole. A small h refers to the minus tolerance of a shaft (such as drill shanks in the catalogue).
ø10 H7 Depth 24
31
H8
30
27
25
22
21
H7
Basic
tolerance
(µm)
20
15
15
9
18
11
13
H6
10
5
5
10
15
20
Hole diameter (mm)