Skip
 Home Product norms ASME B18.3 TABLE 1A
Send your request for quotation

ASME B18.3 TABLE 1A Standard Dimensions for Socket head cap screws, inch series

Stock / Supplier search Send your request for quotation

Hexagon socket head cap screws. The socket head shall have a flat chamfered top surface with smooth or knurled cylindrical sides and a flat bearing surface.

Dimensional Drawing and Technical Diagrams

1774_kKpXAB_B18.3.jpg

Key Dimensions and Technical Parameters

Dimensions in inches - source ASME B18.3 table 1A

Publication date: 2003
d basic thread size Nr of threads x inch dk max k max t min b min S
nom		 M nom
inches mm UNC UNF
0 1.52 - 80 0.096 0.060 0.025 0.5 0.05 0.06
N° 1 1.85 64 72 0.118 0.073 0.031 0.62 0.062 0.072
N° 2 2.18 56 64 0.140 0.086 0.038 0.62 0.078 0.096
N° 3 2.51 48 56 0.161 0.099 0.044 0.62 0.078 0.096
N° 4 2.84 40 48 0.183 0.112 0.051 0.75 0.094 0.111
N° 5 3.18 40 44 0.205 0.125 0.057 0.75 0.094 0.111
N° 6 3.51 32 40 0.226 0.138 0.064 0.75 0.109 0.133
N° 8 4.17 32 36 0.270 0.164 0.077 0.88 0.141 0.168
N° 10 4.83 24 32 0.312 0.190 0.090 0.88 0.156 0.183
1/4 6.35 20 28 0.375 0.250 0.120 1 0.188 0.216
5/16 7.94 18 24 0.469 0.312 0.151 1.12 0.25 0.291
3/8 9.53 16 24 0.562 0.375 0.182 1.25 0.312 0.372
7/16 11.11 14 20 0.656 0.438 0.213 1.38 0.375 0.454
1/2 12.70 13 20 0.750 0.5 0.245 1.5 0.375 0.454
5/8 15.88 11 18 0.938 0.625 0.307 1.75 0.5 0.595
3/4 19.05 10 16 1.125 0.750 0.370 2 0.625 0.620
7/8 22.23 9 14 1.312 0.875 0.432 2.25 0.75 0.698
1 25.40 8 12 1.5 1 0.495 2.5 0.75 0.790
1 1/8 28.58 7 12 1.687 1.125 0.557 2.81 0.875 -
1 1/4 31.75 7 12 1.875 1.250 0.620 3.12 0.875 -
1 3/8 34.93 6 12 2.062 1.375 0.682 3.44 1 -
1 1/2 38.10 6 12 2.25 1.5 0.745 3.75 1 -
1 3/4 28.58 5 - 2.625 1.75 0.870 4.38 1.25 -
2 34.93 4.5 - 3 2 0.995 5 1.5 -
2-1/4 38.10 4.5 - 3.375 2.25 1.20 5.62 1.75 -
2-1/2 63.50 4 - 3.75 2.5 1.245 6.25 1.75 -
2-3/4 69.85 4 - 4.125 2.75 1.370 6.88 2 -
3 76.20 4 - 4.5 3 1.495 7.5 2.25 -
3-1/4 82.55 4 - 4.875 3.25 1.620 8.12 2.25 -
3-1/2 88.90 4 - 5.25 3.5 1.745 8.75 2.75 -
3-3/4 95.25 4 - 5.625 3.75 1.870 9.38 2.75 -
4 101.6 4 - 6 4 1.995 10 3 -

Approx. mass, in kg x1000 pcs, (ρ=7,85 kg/dm3) -
d thread size 4-40 6-32 8-32 10-24 10-32 1/4 5/16 3/8 7/16 1/2 5/8 3/4
nominal length l
1/4 0,53 0,93 1,49 2,19 2,25
5/16 0,58 1,01 1,61 2,36 2,43 4,37
3/8 0,64 1,10 1,74 2,51 2,60 4,65 8,41
7/16 0,70 1,19 1,87 2,68 2,78 4,95 8,88
1/2 0,75 1,27 2,00 2,84 2,97 5,24 9,35 15,07
5/8 0,87 1,45 2,26 3,18 3,32 5,81 10,29 16,43 24,45 36,13
3/4 0,99 1,61 2,50 3,50 3,67 6,39 11,23 17,82 26,33 38,61 69,10
7/8 1,10 1,78 2,76 3,83 4,03 6,97 12,18 19,18 28,21 41,11 73,06
1 1,29 2,07 3,02 4,16 4,39 7,54 13,10 20,56 30,09 43,61 77,02
1-1/4 1,51 2,53 3,74 5,15 5,36 8,70 14,97 23,31 33,86 48,60 84,91 135,22
1-1/2 1,89 2,87 4,26 5,81 6,07 10,60 16,83 26,03 37,62 53,59 92,85 146,84
1-3/4 2,12 3,45 5,05 6,91 7,11 11,75 20,02 30,23 41,40 58,58 100,77 158,46
2 2,49 3,79 5,56 7,56 7,82 13,65 21,89 32,98 47,52 63,55 108,69 170,07
2-1/4 2,72 4,38 6,36 8,66 8,86 14,81 24,75 36,92 51,28 69,59 116,61 181,68
2-1/2 3,10 4,71 6,87 9,32 9,57 16,71 26,73 39,90 56,95 74,56 129,75 193,33
2-3/4 3,33 5,30 7,66 10,41 10,62 17,87 29,60 44,08 60,71 79,56 137,67 204,91
3 3,70 5,63 8,17 11,08 11,33 19,77 31,48 46,82 66,37 85,55 145,59 225,84
3-1/4 20,89 34,38 51,01 70,15 90,55 158,75 237,48
3-1/2 22,83 36,25 53,75 75,83 95,53 166,67 249,06
3-3/4 23,98 39,17 57,93 79,59 101,53 174,59 260,67
4 25,88 41,04 60,68 85,23 106,51 187,76 281,60
4-1/4 27,03 43,95 64,84 88,99 111,51 165,98 293,21
4-1/2 28,94 45,83 67,61 94,68 117,50 203,60 304,82
4-3/4 30,09 48,75 71,78 93,49 122,50 216,79 316,45
5 31,99 50,62 74,54 104,10 127,50 224,71 337,36
5-1/4 33,15 53,55 78,70 107,90 133,48 232,63 348,98
5-1/2 35,05 55,44 81,47 113,54 138,49 245,80 360,60
5-3/4 36,21 58,34 85,63 117,30 143,47 253,71 372,21
6 38,21 60,21 88,37 122,97 149,48 261,63 393,13
6-1/4 39,27 63,12 92,56 126,71 154,46 274,80 404,77
6-1/2 41,18 66,03 95,30 132,40 159,45 282,72 416,36
6-3/4 42,32 67,92 99,49 136,16 165,43 290,64 447,78
7 44,22 69,79 102,22 141,85 170,42 303,80 448,92

Reproduced by permission of DIN Deutsches Institut für Normung e. V. The definitive version for the implementation of this standard is the edition bearing the most recent date of issue, obtainable from Beuth Verlag GmbH, Burggrafenstraße 6, 10787 Berlin, Germany.
WARNING - The datasheets provided by this site (fasten.it) are only advisory in support of the commercial activity and their use by anyone is entirely voluntary. Reliance on their contents for any purpose by anyone is at his/her sole risk and Fasten.it s.r.l./www.fasten.it is not responsible for any loss, claim or damage arising there from.