Stainless Steel Bar Tolerances

ISO Tolerances for Round, Hexagon & Square Bar

(h Tolerances are minus; k Tolerances are plus) - all dimensions in mm

Diameter/Across Flats/Square 5 6 7 8 9 10 11 12 13 16
1 to 3mm .004 .006 .010 .014 .025 .040 .060 .090 .140
>3 to 6mm .005 .008 .012 .018 .030 .048 .075 .120 .180 .750
>6 to 10mm .006 .009 .015 .022 .036 .058 .090 .150 .220 .900
>10 to 18mm .008 .011 .018 .027 .043 .070 .110 .180 .270 1.100
>18 to 30mm .009 .013 .021 .033 .052 .084 .130 .210 .330 1.300
>30 to 50mm .011 .016 .025 .039 .062 .100 .160 .250 .390 1.600
>50 to 80mm .013 .019 .030 .046 .074 .120 .190 .300 .460 1.900
>80 to 120mm .015 .022 .035 .054 .087 .140 .220 .350 .540 2.200
>120 to 180mm - - - .063 .100 .160 .250 .400 .630 2.500
>180 to 250mm - - - .072 .115 .185 .290 .460 .720 2.900
>250 to 315mm - - - .081 .130 .210 .320 .520 .810 3.200