For determining the fundamental deviations K, M and N for standard tolerance grades up to and including IT8
and P to ZC up to and including IT7, the values ∆ from the columns on the right of Table 3 shall be taken into
consideration.

EXAMPLE 1 Tolerance size for a hole 20 K7 E
Table 1: IT7 in the range above 18 mm up to and including 30 mm IT7 =21 µm
Table 3: ∆in the range above 18 mm up to and including 24 mm for IT7 ∆ =8 µm
For K in the range above 18 mm up to and including 24 mm:
Upper limit deviation ES = −2 + ∆ = −2 +8 = +6 µm
Lower limit deviation EI = ES −IT = +6 −21 = −15 µm
From that follows: 
EXAMPLE 2 Toleranced size for a hole 40 U6
Table 1: IT6 in the range above 30 mm up to and including 50 mm IT6 =16 µm
Table 3: ∆in the range above 30 mm up to and including 40 mm for IT6 ∆ =5 µm
For U in the range above 30 mm up to and including 40 mm:
Upper limit deviation ES = −60 + ∆ = −60 +5 = −55 µm
Lower limit deviation EI = ES −IT = −55 −16 = −71 µm
From that follows: 
NOTE For this interference fit, the envelope requirement has been omitted intentionally. For strong interference fits, it
is not necessary to apply the envelope requirement.

Tags: limit deviations EN ISO 286-1