A11 tolerance (hole, IT11)

Hole tolerance class A11 per ISO 286-1:2010: fundamental deviation EI +270 … +1650, grade IT11 (60 µm at ≤ 3 mm to 400 µm at 400–500 mm). For an exact size, open the calculator with A11 selected.

Type
Hole
Grade
IT11
Tolerance
60 … 400 µm
Fund. deviation
EI +270 … +1650 µm

A11 limits by size range

Size (mm)Upper (µm)Lower (µm)Ø max (mm)Ø min (mm)
≤ 3+330+2703.3303.270
3 – 6+345+2706.3456.270
6 – 10+370+28010.37010.280
10 – 14+400+29014.40014.290
14 – 18+400+29018.40018.290
18 – 24+430+30024.43024.300
24 – 30+430+30030.43030.300
30 – 40+470+31040.47040.310
40 – 50+480+32050.48050.320
50 – 65+530+34065.53065.340
65 – 80+550+36080.55080.360
80 – 100+600+380100.600100.380
100 – 120+630+410120.630120.410
120 – 140+710+460140.710140.460
140 – 160+770+520160.770160.520
160 – 180+830+580180.830180.580
180 – 200+950+660200.950200.660
200 – 225+1030+740226.030225.740
225 – 250+1110+820251.110250.820
250 – 280+1240+920281.240280.920
280 – 315+1370+1050316.370316.050
315 – 355+1560+1200356.560356.200
355 – 400+1710+1350401.710401.350
400 – 450+1900+1500451.900451.500
450 – 500+2050+1650502.050501.650

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 A11

A11 denotes a hole tolerance zone with large clearance deviation in the ISO 286 system. It is used in A11/h11 (Shaft-basis equivalent of H11/a11.).

At Ø25 mm A11 is +0.430 / +0.300 mm, i.e. 25.300 to 25.430 mm.

How the limits are calculated

A11 uses grade IT11 (a standard tolerance of 130 µm at 18–30 mm). Fundamental deviation: EI = −es of the same shaft letter; IT11 sets the width above EI. See the fundamental deviation table for every letter. Values per ISO 286-1:2010.

Fits using A11

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