Thread Tolerances For Screws and Nuts

for Screws and Nut Threads
Limits of Sizes for Bolt & Nut Threads

Reference No.: ISO 965/1-1980, ISO 965/2-1980
COARSE AND FINE THREAD SERIES
TOLERANCE DESIGNATION
BOLT THREADS
6 h for sizes up to M 1, 4
6 g for sizes M 1, 6 and larger
NUT THREADS
5 H for sizes upto M 1, 4
6 H for sizes M 1, 6 and larger

Note : Tolerances apply to the threads before coating. After coating theactual thread profile shall not exceed the maximum tolerance H or h limits. Thin (electroplate-type) coating may be acceptable.

Limits for Metric (standard) Coarse Threads According To ISO 965

Thread Size in mmEngagement LengthMajor Diameter(d)Pitch Diameter(d2)
 fromtomax.min.max.min.
M10,61,71,0000,9330,8380,785
M1.20,61,71,1001,0330,9380,885
M1.40, 721,4001,3251,2051,149
M1.60, 82, 61,5811,4961,3541,291
M1.80, 82, 61,7811,6961,5541,491
M2131,9811,8861,7211,654
M2.51, 33, 82,1802,0801,8881,817
M31, 54, 52,9802,8742,6552,580
M3.51, 753,4793,3543,0893,004`
M4263,9783,8383,5233,433
M52, 57, 54,9764,8264,4564,361
M6395,9745,7945,3245,212
M7336,9746,7946,3246,212
M84127,9727,7607,1607,042
M105159,9689,7328,9948,862
M1261811,96611,70110,82910,679
M1482413,96213,68212,66312,503
M1682415,96215,68214,66314,503
M18103017,95817,62316,33416,164
M20103019,95819,62318,33418,164
M22103021,95821,62320,33420,164
M24123623,95223,57722,00321,803
M27123626,95226,57725,00324,803
M30154529,94729,52227,67427,462
M33154532,94732,52230,67430,462
M36185335,94035,46533,34233,118
M39185338,94038,46536,34236,118

Limits For Metric Fine Threads According To ISO 965

Thread Size in mmLength of Thread engagementMAJOR DIAMETERPITCH DIAMETER
overup to and incl.max.min.max.min.
M8x1397,9747,7947,3247,212
M10x1.254129,9729,7609,1609,042
M12x1.254, 51311,97211,76011,16011,028
M14x1.55, 61613,96813,73212,99412,854
M16x1.55, 61615,96815,73214,99414,854
M18x1.55, 61617,96817,73216,99416,854
M20x1.55, 61619,96819,73218,99418,854
M22x1.55, 61621,96821,73220,99420,854
M24x28, 52523,96223,68222,66322,493
M27x28, 52526,96226,68225,66325,493
M30x28, 52529,96229,68228,66328,493
M33x28, 52532,96232,68231,66331,493
M36x3123635,95235,57734,00333,803
M39x3123638,95238,57737,00336,803

*All information is strictly informative