P9 tolerance (hole, IT9)

Hole tolerance class P9 per ISO 286-1:2010: fundamental deviation ES −6 … −68, grade IT9 (25 µm at ≤ 3 mm to 155 µm at 400–500 mm). For an exact size, open the calculator with P9 selected.

Type
Hole
Grade
IT9
Tolerance
25 … 155 µm
Fund. deviation
ES −6 … −68 µm

P9 limits by size range

Size (mm)Upper (µm)Lower (µm)Ø max (mm)Ø min (mm)
≤ 3−6−312.9942.969
3 – 6−12−425.9885.958
6 – 10−15−519.9859.949
10 – 14−18−6113.98213.939
14 – 18−18−6117.98217.939
18 – 24−22−7423.97823.926
24 – 30−22−7429.97829.926
30 – 40−26−8839.97439.912
40 – 50−26−8849.97449.912
50 – 65−32−10664.96864.894
65 – 80−32−10679.96879.894
80 – 100−37−12499.96399.876
100 – 120−37−124119.963119.876
120 – 140−43−143139.957139.857
140 – 160−43−143159.957159.857
160 – 180−43−143179.957179.857
180 – 200−50−165199.950199.835
200 – 225−50−165224.950224.835
225 – 250−50−165249.950249.835
250 – 280−56−186279.944279.814
280 – 315−56−186314.944314.814
315 – 355−62−202354.938354.798
355 – 400−62−202399.938399.798
400 – 450−68−223449.932449.777
450 – 500−68−223499.932499.777

Deviations at the upper end of each range (Ø columns use that size); use the calculator for the exact size. — : not defined by ISO 286 for that size. Upper/Lower (mm) and inch columns are shown on wider screens.

About P9

P9 denotes a hole tolerance zone with press deviation in the ISO 286 system.

At Ø25 mm P9 is −0.022 / −0.074 mm, i.e. 24.926 to 24.978 mm.

How the limits are calculated

P9 uses grade IT9 (a standard tolerance of 52 µm at 18–30 mm). Fundamental deviation: ES = −ei + Δ (Δ = ITn − IT(n−1), applied up to IT8 for K/M/N and IT7 otherwise); IT9 sets the width below ES. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.

Related classes

P6P7