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| METRIC TOLERANCES (Nominal Sizes) |
| mm |
H11 |
H10 |
H9 |
H8 |
H7 |
| > 1 to 3 |
0.060 |
0.040 |
0.025 |
0.014 |
0.010 |
| > 3 to 6 |
0.075 |
0.048 |
0.030 |
0.018 |
0.012 |
| > 6 to 10 |
0.090 |
0.058 |
0.036 |
0.022 |
0.015 |
| > 10 to 18 |
0.110 |
0.070 |
0.043 |
0.027 |
0.018 |
| > 18 to 30 |
0.130 |
0.084 |
0.052 |
0.033 |
0.021 |
| > 30 to 50 |
0.160 |
0.100 |
0.062 |
0.039 |
0.025 |
| > 50 to 80 |
0.190 |
0.120 |
0.074 |
0.046 |
0.030 |
| > 80 to 120 |
0.220 |
0.140 |
0.087 |
0.054 |
0.035 |
| > 120 to 180 |
0.250 |
0.160 |
0.100 |
0.063 |
0.040 |
| INCH TOLERANCES (Nominal Sizes) |
| inches |
H11 |
H10 |
H9 |
H8 |
H7 |
| > 3/64 to 1/8 |
0.00240 |
0.00157 |
0.00098 |
0.00055 |
0.00039 |
| > 1/8 to 15/64 |
0.00295 |
0.00189 |
0.00118 |
0.00071 |
0.00047 |
| > 15/64 to 25/64 |
0.00354 |
0.00228 |
0.00142 |
0.00087 |
0.00059 |
| > 25/64 to 45/64 |
0.00433 |
0.00275 |
0.00169 |
0.00106 |
0.00071 |
| > 45/64 to 1 3/16 |
0.00511 |
0.00331 |
0.00205 |
0.00130 |
0.00082 |
| > 1 3/16 to 2 |
0.00629 |
0.00393 |
0.00244 |
0.00153 |
0.00098 |
| > 2 to 3 1/8 |
0.00748 |
0.00474 |
0.00291 |
0.00181 |
0.00118 |
| > 3 1/8 to 4 3/4 |
0.00866 |
0.00551 |
0.00342 |
0.00213 |
0.00137 |
| > 4 3/4 to 7 3/32 |
0.00984 |
0.00629 |
0.00393 |
0.00248 |
0.00157 |
Tolerances for Cold Drawn Steel Bar to BS 970: Part 3: 1991
|
SECTION
|
SIZE (mm)
|
TOLERANCES (mm)
|
|
Round
|
Diameter
|
|
6 18
|
+ 0 � 0.070
|
|
> 18 30
|
+ 0 � 0.085
|
|
> 30 50
|
+ 0 � 0.100
|
|
> 50 80
|
+ 0 � 0.120
|
|
> 80 100
|
+ 0 � 0.140
|
|
Square & Hexagonal
|
Across Flats
|
|
18
|
+ 0 � 0.090
|
|
> 18 30
|
+ 0 � 0.110
|
|
> 30 50
|
+ 0 � 0.130
|
|
> 50 80
|
+ 0 � 0.160
|
|
> 80
|
by arrangement
|
|
Flat
|
Width
|
|
> 10 18
|
+ 0 � 0.110
|
|
> 18 30
|
+ 0 � 0.130
|
|
> 30 50
|
+ 0 � 0.160
|
|
> 50 80
|
+ 0 � 0.190
|
|
> 80 100
|
+ 0 � 0.220
|
|
> 100 120
|
+ 0 � 0.350
|
|
> 120 180
|
+ 0 � 0.400
|
|
> 180
|
by arrangement
|
|
Flat
|
Thickness
|
|
10 18
|
+ 0 � 0.110
|
|
> 18 30
|
+ 0 � 0.130
|
|
> 30 50
|
+ 0 � 0.250
|
|
> 50
|
by arrangement
|
Tolerances should be used for guidance only, as these are conditional on the material being measured within the parameters specified by BS 970: Part 3: 1991. For Weights of Steel please refer to CONVERSION TABLES & FACTORS.
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