Proof Loads for Fasteners

Proof Loads For Screws
ISO Metric (Coarse) Threads ISO 898/I-1988

Nominal Diameter Of Thread d(mm) Pitch
P(mm)
Nomincal Stress Area
As (mm2)
Property Class
3.6 4.6 4.8 5.6 5.8 6.8 8.8 9.8 10.9 12.9
Proof Load (As . Ap),N
3 0.50 5.03 910 1130 1560 1410 1910 2210 2920 3270 4180 4880
3.5 0.60 6.78 1220 1530 2100 1900 2580 2980 3940 4410 5630 6580
4 0.70 8.78 1580 1980 2770 2460 3340 3860 5100 5710 7290 8520
5 0.80 14.20 2560 3200 4400 3980 5400 6250 8230 9230 11800 13800
6 1.00 20.10 3620 4520 6230 5630 7640 8840 11600 13100 16700 19500
7 1.00 28.90 5200 6500 8920 8090 11000 12700 16800 18800 24000 28000
8 1.25 36.60 6590 8240 11400 10200 13900 16100 21200 23800 30400 35500
10 1.50 58.00 10400 13000 18000 16200 22000 25500 33700 37700 48100 56300
12 1.75 84.30 15200 19000 26100 23600 32000 37100 489001) 54800 70000 81800
14 2.00 115 20700 25900 35600 32200 43700 50600 667001) 74800 95500 112000
16 2.00 157 28300 35300 48700 44000 59700 69100 910001) 102000 130000 152000
18 2.50 192 34600 43200 59500 53800 73000 84500 11500   159000 186000
20 2.50 245 44100 55100 76000 68600 93100 108000 147000   203000 238000
22 2.50 303 54500 68200 93900 84800 115000 133000 182000   252000 294000
24 3.00 353 63500 79400 109000 98800 134000 155000 212000   293000 342000
27 3.00 459 82600 103000 142000 128000 174000 202000 275000   381000 445000
30 3.50 561 101000 126000 174000 157000 213000 247000 337000   466000 544000
33 3.50 694 125000 156000 215000 194000 264000 305000 416000   570000 673000
36 4.00 817 147000 184000 253000 229000 310000 359000 490000   678000 792000
39 4.00 976 176000 220000 303000 273000 371000 429000 586000   810000 947000
1)For structural steel screws 50700,68800 and 94500 N

Proof Loads For Screws
ISO Metric (Fine) Threads ISO 898/I-1988

Nominal Diameter Of Thread d(mm) Pitch
P(mm)
Nomincal Stress Area
As (mm2)
Property Class
3.6 4.6 4.8 5.6 5.8 6.8 8.8 9.8 10.9 12.9
Proof Load (As . Ap),N
8 1.00 39.2 7060 8820 12200 11000 14900 17200 22700 25500 32500 38000
10 1.25 61.2 11000 13800 19000 17100 23300 26900 33500 39800 50800 59400
12 1.25 92.1 16600 20700 28600 25800 35000 40500 53400 59900 76300 89300
14 1.50 125 22500 28100 38800 35000 47500 55000 72500 81200 104000 121000
16 1.50 167 30100 27600 51800 46800 63500 73500 96900 109000 139000 162000
18 1.50 216 38900 48600 67000 60500 82100 95000 130000   179000 210000
20 1.50 272 49000 61200 84300 76200 103000 120000 163000   226000 264000
22 1.50 333 59900 74900 103000 93200 126000 146000 200000   276000 323000
24 2.00 384 69100 86400 119000 108000 146000 169000 230000   319000 372000
27 2.00 496 89300 112000 154000 139000 188000 218000 298000   412000 481000
30 2.00 621 112000 140000 192000 171000 236000 273000 373000   515000 602000
33 2.00 761 137000 171000 236000 213000 289000 335000 457000   632000 738000
36 3.00 865 156000 195000 268000 242000 329000 381000 519000   718000 838000
39 3.00 1030 185000 232000 319000 288000 391000 453000 618000   855000 999000

Proof Loads For Nuts (Coarse Thread)
According to DIN 934 and DIN 985 (Ref. DIN 267/4)

Thread
Size
Pitch
P(mm)
Nominal Stress Area of Test Mandrel As mm2 Property Class
4 5 6 8 10 12
Proof Load (As * Sp), in N
M3  0.50 5.03   2500 3000 4000 5000 6000
M3.5  0.60 6.78   3400 4050 5400 6800 8150
M4  0.70 8.78   4400 5250 7000 8750 10500
M5  0.80 14.2   7100 8500 11400 11400 17000
M6  1.00 20.1   10000 12000 16000 20000 24000
M7  1.00 28.9   14500 17300 23000 29000 34700
M8  1.25 36.6   18300 22000 29000 36500 43000
M10  1.50 58.0   29000 35000 46000 58000 69500
M12 1.75 84.5   42100 50500 67000 84000 100000
M14  2.00 115   57500 69000 92000 115000 138000
M16  2.00 157   78500 94000 126000 157000 188000
M18  2.50 192 76800 96000 115000 154000 192000 230000
M20  2.50 245 98000 122000 147000 196000 245000 294000
M22  2.50 303 121000 151000 182000 242000 303000 364000
M24  3.00 353 141000 176000 212000 282000 353000 423000
M27  3.00 459 184000 230000 276000 367000 459000 550000
M30  3.50 561 224000 280000 336000 448000 561000 673000
M33  3.50 694 277000 347000 416000 555000 694000 833000
M36  4.00 817 327000 408000 490000 653000 817000 980000
M39  4.00 976 390000 488000 585000 780000 976000 1170000
The above proof loads are also valid for nuts where the property class marking is enclosed by two vertical lines |8|
Conversion Factor: 1N = 0.2248 lb.

Proof Loads For Nuts (Fine Thread)
According to DIN 934 and DIN 985 (Ref. DIN 267/4)

Thread
Size
Pitch
P(mm)
Nominal Stress Area of Test Mandrel As mm2 Property Class
5 6 8 10 12
Proof Load (As * Sp), in N
M8 1.00 39.2 19600 23500 31000 39000 47000
M10 1.00 64.5 32200 38700 51500 64500 77500
M10 1.25 61.2 30600 37000 49000 61000 73500
M12 1.25 92.1 46000 55000 74000 92000 110000
M12 1.50 88.1 44000 53000 70000 88000 106000
M14 1.50 125 62200 75000 100000 125000 150000
M16 1.50 167 83500 100000 134000 167000 200000
M18 1.50 216 108000 129000 173000 216000 259000
M18 2.00 204 102000 122000 163000 204000 245000
M20 1.50 272 136000 163000 218000 272000 326000
M20 2.00 258 129000 155000 206000 258000 310000
M22 1.50 333 166000 200000 266000 333000 400000
M22 2.00 318 159000 191000 254000 318000 382000
M24 2.00 384 192000 230000 307000 384000 460000
M27 2.00 496 248000 298000 397000 496000 595000
M30 2.00 621 310000 373000 497000 621000 745000
M33 2.00 761 380000 456000 608000 761000 914000
M36 3.00 865 432000 519000 692000 865000 1040000
M39 3.00 1030 501000 618000 825000 1030000 1240000
The above proof loads are also valid for nuts where the property class marking is enclosed by two vertical lines |8|
Conversion Factor: 1N = 0.2248 lb.

*All information is strictly informative