B11 tolerance (hole, IT11)

Hole tolerance class B11 per ISO 286-1:2010: fundamental deviation EI +140 … +840, grade IT11 (60 µm at ≤ 3 mm to 400 µm at 400–500 mm). For an exact size, open the calculator with B11 selected.

Type
Hole
Grade
IT11
Tolerance
60 … 400 µm
Fund. deviation
EI +140 … +840 µm

B11 limits by size range

Size (mm)Upper (µm)Lower (µm)Ø max (mm)Ø min (mm)
≤ 3+200+1403.2003.140
3 – 6+215+1406.2156.140
6 – 10+240+15010.24010.150
10 – 14+260+15014.26014.150
14 – 18+260+15018.26018.150
18 – 24+290+16024.29024.160
24 – 30+290+16030.29030.160
30 – 40+330+17040.33040.170
40 – 50+340+18050.34050.180
50 – 65+380+19065.38065.190
65 – 80+390+20080.39080.200
80 – 100+440+220100.440100.220
100 – 120+460+240120.460120.240
120 – 140+510+260140.510140.260
140 – 160+530+280160.530160.280
160 – 180+560+310180.560180.310
180 – 200+630+340200.630200.340
200 – 225+670+380225.670225.380
225 – 250+710+420250.710250.420
250 – 280+800+480280.800280.480
280 – 315+860+540315.860315.540
315 – 355+960+600355.960355.600
355 – 400+1040+680401.040400.680
400 – 450+1160+760451.160450.760
450 – 500+1240+840501.240500.840

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 B11

B11 denotes a hole tolerance zone with large clearance deviation in the ISO 286 system.

At Ø25 mm B11 is +0.290 / +0.160 mm, i.e. 25.160 to 25.290 mm.

How the limits are calculated

B11 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.

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