ISO 898-2 Specification

This part of ISO 898 specifies mechanical and physical properties of nuts with coarse thread and fine pitch thread made of carbon steel and alloy steel when tested at an ambient temperature range of 10 °C to 35 °C. Nuts conforming to the requirements of this part of ISO 898 are evaluated at that ambient temperature range. It is possible that they do not retain the specified mechanical and physical properties at elevated and/or lower temperatures.

ISO 898-2 Chemical Composition

Thread Property class Material and nut heat treatment Chemical composition limit (cast analysis %)
c
max.		 Mn
min.		 p
max.		 s
max.
Coarse thread 04C   Carbon steel,d 0.58 0.25 0.060 0.150
osc   Carbon steel,QTe 0.58 0.30 0.048 0.058
Sb   Carbon steel,d 0.58 - 0.060 0.150
Sb   Carbon steel,d 0.58 - 0.060 0.150
8 Highnut (style 2) Carbon steel,d 0.58 0.25 0.060 0.150
8 Regular nut (style 1) D s M16 Carbon steel,d 0.58 0.25 0.060 0.150
3c Regular nut (style 1) D > M16 Carbon steel,QTe 0.58 0.30 0.048 0.058
9   Carbon steel,d 0.58 0.25 0.060 0.150
1oc   Carbon steel,QTe 0.58 0.30 0.048 0.058
12c   Carbon steel,QTe 0.58 0.45 0.048 0.058
Fine pitch thread 04b   Carbon steel,d 0.58 0.25 0.060 0.150
osc   Carbon steel,QTe 0.58 0.30 0.048 0.058
5b   Carbon steel,d 0.58 - 0.060 0.150
5b D SM16 Carbon steel,d 0.58 - 0.060 0.150
5b D > M16 Carbon steel;QTe 0.58 0.30 0.048 0.058
8 High nut (style 2) Carbon steet,d 0.58 0.25 0.060 0.150
3c Regular nut (style 1) Carbon steel,QTe 0.58 0.30 0.048 0.058
1oc   Carbon steel,QTe 0.58 0.30 0.048 0.058
12C   Carbon steel,QTe 0.58 0.45 0.048 0.058
Note:

QT = Quenched and tempered nuts.
“—“ No limit specified.
a. In case of dispute, the product analysis applies.
b. Nuts of these property classes may be manufactured from free-cutting steel upon agreement between the purchaser and the manufacturer; in such a case, sulfur, phosphorus and lead are permissible with the following maximum contents: S: 0,34 %; P: 0,11 %; Pb: 0,35%.
c. Alloying elements may be added, provided the mechanical properties required in Clause 7 are fulfilled.
d. This may be quenched and tempered at the manufacturer’s discretion.
e. For materials of these property classes, there shall be sufficient hardenability to ensure a structure consisting of approximately 90 % martensite in the “as-hardened” condition before tempering in the threaded area of the nut as specified in Figure 3.

ISO 898-2 Mechanical properties

Proof load values for nuts with coarse thread

Thread D              Pitch p Proof load a, N Property class
04 05 5 6 8 9 10 12
MS 0.8 5400 7 100 8250 9 500 12 140 13000 14800 16 300
M6 1 7 640 10 000 11 700 13 500 17 200 18400 20 900 23100
M7 1 11 000 14500 16 800 19 400 24 700 26 400 30 100 33200
MS 1.25 13900 18300 21 600 24 900 31800 34 400 38 100 42 500
M10 1.5 22 000 29 000 34 200 39 400 50 500 54 500 60 300 67 300
M12 1.75 32 000 42 200 51400 59 000 74 200 80 100 88500 100 300
M14 2 43 700 57 500 70 200 80 500 101 200 109 300 120 800 136 900
M16 2 59 700 78500 95 800 109 900 138200 149 200 164 900 186 800
M18 2.5 73000 96 000 121 000 138200 176 600 176 600 203 500 230 400
M20 2.5 93 100 122 500 154 400 176 400 225 400 225400 259 700 294 000
M22 2.5 115 100 151 500 190 900 218200 278 800 278800 321 200 363 600
M24 3 134 100 176 500 222 400 254 200 324 800 324 800 374 200 423 600
M27 3 174 400 229 500 289 200 330 500 422 300 422 300 486 500 550 800
M30 3.5 213 200 280 500 353 400 403 900 516 100 516 100 594 700 673200
M33 3.5 263 700 347 000 437 200 499 700 638 500 638 500 735600 832 800
M36 4 310 500 408500 514700 588200 751600 751 600 866 000 980 400
M39 4 370 900 488 000 614 900 702 700 897 900 897 900 1035000 1 171 000
Note:

a. For the application of thin nuts, it should be considered that the stripping load is lower than the proof load of a nut with full loadability (see Annex A).

Proof load values for nuts with fine pitch thread

Thread D × P Proof load a, N Property class
04 05 5 6 8 10 12
M8>1 14 900 19 600 27 000 30 200 37 400 43100 47 000
M10> 1,25 23300 30 600 44 200 47 100 58400 67 300 73400
M10>1 24 500 32 200 44 500 49 700 61 600 71 000 77 400
M12>1,5 33500 44 000 60 800 68 700 84 100 97 800 105 700
M12x1,25 35 000 46 000 63 500 71 800 88 000 102 200 110 500
M14>1,5 47500 62 500 86 300 97 500 119 400 138 800 150 000
M16>1,5 63500 83 500 115 200 130 300 159 500 185 400 200 400
M18><2 77 500 102 000 146900 177 500 210 100 220 300 -
M18>1,5 81 700 107 500 154 800 187 000 221 500 232 200 -
M20>2 98 000 129 000 185 800 224 500 265 700 278 600 -
M20><1,5 103400 136 000 195 800 236 600 280 200 293 800 -
M22>2 120 800 159 000 229 000 276 700 327 500 343 400 -
M22><1,5 126 500 166 500 239800 289 700 343000 359 600 -
M24>2 145 900 192 000 276 500 334 100 395500 414700 -
M27x2 188500 248 000 351 100 431 500 510 900 535700 -
M30>2 236 000 310 500 447 100 540 300 639 600 670 700 -
M33>2 289 200 380 500 547 900 662 100 783800 821 900 -
M36>3 328 700 432 500 622 800 804 400 942 800 934 200 -
M39>3 391 400 515 000 741 600 957 900 1 123000 1 112 000 -
Note:

a. For the application of thin nuts, it should be considered that the stripping load is lower than the proof load of a nut with full loadability, see Annex A.