Nord-Lock Group About Nord-Lock Torquelator | Nord-Lock

Torque Guidelines

Use our guidelines to get an indication of torque and preload values for any size bolt M3 – M42, using Nord-Lock washers and a variety of lubrication methods. Please note that values may vary with different coating systems and friction coefficients.

 

      Oil, GF = 75%
μth = 0.15, μh = 0.19		 Cu/C paste, GF = 75%
μth = 0.13, μh = 0.18		 Dry, GF = 62%
μth = 0.18, μh = 0.2
Bolt Size Product Name Pitch
[mm]		 Torque
[Nm]		 Clamp Load
[kN]		 Torque
[Nm]		 Clamp Load
[kN]		 Torque
[Nm]		 Clamp Load
[kN]
M3 NL3 0.5 1.7 2.4 1.5 2.4 1.5 2
M4 NL4 0.7 3.8 4.2 3.6 4.2 3.5 3.5
M5 NL5 0.8 7.5 6.8 6.9 6.8 6.8 5.6
M6 NL6 1 13 9.7 12.1 9.7 12 8
M8 NL8 1.25 32 18 29 18 29 15
M10 NL10 1.5 62 28 57 28 56 23
M12 NL12 1.75 107 40 99 40 97 33
M14 NL14 2 170 55 157 55 155 46
M16 NL16 2 260 75 240 75 237 62
M18 NL18 2.5 364 92 336 92 331 76
M20 NL20 2.5 510 118 470 118 464 97
M22 NL22 2.5 696 146 642 146 634 120
M24 NL24 3 878 169 809 169 800 140
M27 NL27 3 1 ,284 221 1183 221 1172 182
M30 NL30 3.5 1750 269 1613 269 1596 222
M33 NL33 3.5 2360 333 2173 333 2155 275
M36 NL36 4 3043 392 2803 392 2776 324
M39 NL39 4 3931 468 3619 468 3589 387
M42 NL42 4.5 4860 538 4476 538 4436 445

 

Cu/C paste = Copper/graphite paste
Oil = WD40 has been used.
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient
1 N = 0.225 lb
1 Nm = 0.738 ft-lb


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

 

      Oil, GF = 75%
μth = 0.15, μh = 0.17		 Cu/C paste, GF = 75%
μth = 0.13, μh = 0.17		 Dry, GF = 62%
μth = 0.18, μh = 0.18
Product name Bolt Size Pitch
[mm]		 Torque
[Nm]		 Clamp Load
[kN]		 Torque
[Nm]		 Clamp Load
[kN]		 Torque
[Nm]		 Clamp Load
[kN]
NL3  M3  0.5  0.8  1.2  0.7  1.2  0.7  1.0 
NL4  M4  0.7  1.8  2.1  1.7  2.1  1.6  1.7 
NL5  M5  0.8  3.5  3.4  3.4  3.4  3.2  2.8 
NL6  M6  1.0  6.2  4.8  5.9  4.8  5.6  4.0 
NL8  M8  1.25  15 9.0  14 9.0  14 7.0 
NL10  M10  1.5  29 14 28 14 27 12
NL12  M12  1.75  50 20 48 20 46 17
NL14  M14  2.0  80 28 76 28 73 23
NL16  M16  2.0  123 38 116 38 112 31
NL18  M18  2.5  172 46 163 46 157 38
NL20  M20  2.5  240 59 228 59 220 49
NL22  M22  2.5  328 73 311 73 301 60
NL24  M24  3.0  414 85 392 85 379 70
NL27  M27  3.0  605 110 573 110 555 91
NL30  M30  3.5  825 135 782 135 757 111
NL33  M33  3.5  1113 166 1053 166 1022 138
NL36  M36  4.0  1435 196 1358 196 1316 162
NL39  M39  4.0  1853 234 1753 234 1701 194
NL42  M42  4.5  2291 269 2169 269 2103 222

 

Cu/C paste = Copper/graphite paste
Oil = WD40 has been used.
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient
1 N = 0.225 lb
1 Nm = 0.738 ft-lb


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

 

      Oil, GF = 71%
μth = 0.15, μh = 0.15		 Cu/C paste, GF = 75%
μth = 0.13, μh = 0.15
Bolt Size Product Name Pitch
[mm]		 Torque
[Nm]		 Clamp Load
[kN]		 Torque
[Nm]		 Clamp Load
[kN]
M3 NL3 0.5 2 3.2 2 3.4
M4 NL4 0.7 4.5 5.6 4.5 5.9
M5 NL5 0.8 8.9 9.1 8.9 9.6
M6 NL6 1 15.5 12.9 15.5 13.6
M8 NL8 1.25 37 23 37 25
M10 NL10 1.5 73 37 73 39
M12 NL12 1.75 126 54 126 57
M14 NL14 2 201 74 201 78
M16 NL16 2 307 100 306 106
M18 NL18 2.5 430 123 429 130
M20 NL20 2.5 602 156 600 165
M22 NL22 2.5 821 194 818 205
M24 NL24 3 1036 225 1034 238
M27 NL27 3 1514 294 1509 310
M30 NL30 3.5 2064 358 2058 378
M33 NL33 3.5 2782 443 2772 468
M36 NL36 4 3589 522 3576 551
M39 NL39 4 4632 624 4613 659
M42 NL42 4.5 5731 716 5709 757

 

Cu/C paste = Copper/graphite paste
Oil = WD40 has been used.
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient
1 N = 0.225 lb
1 Nm = 0.738 ft-lb


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

 

      Oil, GF=71%
μth= 0.15, μh= 0.13		 Cu/C paste, GF=75%
μth = 0.13, μh = 0.14
Bolt Size Product Name Pitch
[mm]		 Torque
[Nm]		 Clamp Load
[kN]		 Torque
[Nm]		 Clamp Load
[kN]
M3 NL3 0.5 2.2 3.9 2.3 4.1
M4 NL4 0.7 5.1 6.7 5.3 7.1
M5 NL5 0.8 10 10.9 10.3 11.5
M6 NL6 1 17.4 15.4 18 16.3
M8 NL8 1.25 42 28 43 30
M10 NL10 1.5 82 44 85 47
M12 NL12 1.75 142 65 146 68
M14 NL14 2 226 89 233 94
M16 NL16 2 345 120 355 127
M18 NL18 2.5 483 148 498 156
M20 NL20 2.5 676 188 696 198
M22 NL22 2.5 921 233 948 246
M24 NL24 3 1165 270 1199 286
M27 NL27 3 1700 352 1749 372
M30 NL30 3.5 2316 430 2386 454
M33 NL33 3.5 3124 532 3213 562
M36 NL36 4 4029 626 4145 662
M39 NL39 4 5199 748 5346 790
M42 NL42 4.5 6434 860 6617 908

 

Cu/C paste = Copper/graphite paste 
Oil = WD40 has been used.
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient
1 N = 0.225 lb
1 Nm = 0.738 ft-lb


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

 

      A2-50, A4-50 Cu/C paste 
GF = 65%, μth= 0.13, μh= 0.13		 A4-70 Cu/C paste 
GF = 65%, μth= 0.13, μh= 0.13		 A4-80 Cu/C paste 
GF = 65%, μth = 0.13, μh = 0.13
Bolt Size Product Name Pitch
[mm]		 Torque
[Nm]		 Clamp Load
[kN]		 Torque
[Nm]		 Clamp Load
[kN]		 Torque
[Nm]		 Clamp Load
[kN]
M3 NL3 ss 0.5 0.4  0.7  0.8 1.5 1.1 2
M4 NL4 ss 0.7 0.9  1.2  1.8 2.6 2.4 3.4
M5 NL5 ss 0.8 1.7  1.9  3.6 4.1 4.8 5.5
M6 NL6 ss 1 2.9  2.7  6.3 5.9 8.4 7.8
M8 NL8 ss 1.25 7.0  5.0  15 11 20 14
M10 NL10 ss 1.5 14 8 30 17 39 23
M12 NL12 ss 1.75 24 12 51 25 68 33
M14 NL14 ss 2 38 16 81 34 108 45
M16 NL16 ss 2 58 21 124 46 165 61
M18 NL18 ss 2.5 81 26 173 56 231 75
M20 NL20 ss 2.5 113 33 243 72 323 95
M22 NL22 ss 2.5 149 39 330 89 440 118
M24 NL24 ss 3 195 48 418 103 557 137
M27 NL27 ss 3 284 63 609 134 812 179
M30 NL30 ss 3.5 388 77 831 164 1108 219
M36 NL36ss 4 674 111 1444 239 1925 319

 

Cu/C paste = Copper/graphite paste 
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient
1 N = 0.225 lb
1 Nm = 0.738 ft-lb


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

 

      A4-70 Cu/C paste 
GF = 65%, μth= 0.13, μh= 0.13		 A4-80 Cu/C paste 
GF = 65%, μth = 0.13, μh = 0.13
Bolt Size Product Name Pitch
[mm]		 Torque
[Nm]		 Clamp Load
[kN]		 Torque
[Nm]		 Clamp Load
[kN]
M3 NL3 ss-254 0.5 0.8 1.5 1.1 2
M4 NL4 ss-254 0.7 1.8 2.6 2.4 3.4
M5 NL5 ss-254 0.8 3.6 4.1 4.8 5.5
M6 NL6 ss-254 1 6.3 5.9 8.4 7.8
M8 NL8 ss-254 1.25 15 11 20 14
M10 NL10 ss-254 1.5 30 17 39 23
M12 NL12 ss-254 1.75 51 25 68 33
M14 NL14 ss-254 2 81 34 108 45
M16 NL16 ss-254 2 124 46 165 61
M18 NL18 ss-254 2.5 173 56 231 75
M20 NL20 ss-254 2.5 243 72 323 95
M22 NL22 ss-254 2.5 330 89 440 118
M24 NL24 ss-254 3 418 103 557 137
M27 NL27 ss-254 3 609 134 812 179
M30 NL30 ss-254 3.5 831 164 1108 219
M36 NL36ss-254 4 1444 239 1925 319

 

Cu/C paste = Copper/graphite paste
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient
1 N = 0.225 lb
1 Nm = 0.738 ft-lb


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

 

      Oil, GF = 75%
μth = 0.15, μh = 0.19		 Cu/C paste, GF = 75%
μth = 0.13, μh = 0.18		 Dry, GF = 62%
μth = 0,18, μh = 0,2
Bolt Size Product Name Pitch
[mm]		 Torque
[Nm]		 Clamp Load
[kN]		 Torque
[Nm]		 Clamp Load
[kN]		 Torque
[Nm]		 Clamp Load
[kN]
M6 NLX6 1 13 9.7 12 9.7 12 8
M8 NLX8 1.25 32 18 29 18 29 15
M10 NLX10 1.5 62 28 57 28 56 23
M12 NLX12 1.75 107 40 99 40 97 33
M14 NLX14 2 170 55 157 55 155 46
M16 NLX16 2 260 75 240 75 237 62
M20 NLX20 2.5 510 118 470 118 464 97

 

Cu/C paste = Copper/graphite paste 
Oil = WD40 has been used.
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient
1 N = 0.225 lb
1 Nm = 0.738 ft-lb


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

 

      Oil, GF = 71%
μth = 0.15, μh = 0.13		 Cu/C paste, GF = 75%
μth = 0.13, μh = 0.14
Bolt Size Product Name Pitch
[mm]		 Torque
[Nm]		 Clamp Load
[kN]		 Torque
[Nm]		 Clamp Load
[kN]
M6 NLX6 1 15.5 12.9 15.5 13.6
M8 NLX8 1.25 37 23 37 25
M10 NLX10 1.5 73 37 73 39
M12 NLX12 1.75 126 54 126 57
M14 NLX14 2 201 74 201 78
M16 NLX16 2 307 100 306 106
M20 NLX20 2.5 602 156 600 165

 

Cu/C paste = Copper/graphite paste 
Oil = WD40 has been used.
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient
1 N = 0.225 lb
1 Nm = 0.738 ft-lb


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

 

      Oil, GF = 75%
μth = 0.08, μh = 0.18		 Cu/C paste, GF = 75%
μth = 0.08, μh = 0.19		 Dry, GF = 62%
μth = 0.19, μh = 0.2
Bolt Size Product Name Pitch
[TPI]		 Torque
[ftlb]		 Clamp Load
[lb]		 Torque
[ftlb]		 Clamp Load
[lb]		 Torque
[ftlb]		 Clamp Load
[lb]
#5 NL3 40 1.1 559 1.1 559 1.1 410
#6 NL3.5 32 1.4 640 1.5 640 1.4 469
#8 NL4 32 2.5 983 2.6 983 2.5 721
#10 NL5 24 3.7 1234 3.9 1234 3.7 905
1/4 NL1/4" 20 8.8 2235 9.1 2235 8.8 1639
5/16 NL8 18 18 3674 18 3674 18 2694
3/8 NL3/8" 16 31 5424 32 5424 31 3978
7/16 NL11 14 49 7439 50 7439 50 5455
1/2 NL1/2" 13 75 9920 77 9920 76 7271
9/16 NL14 12 107 12712 111 12712 109 9322
5/8 NL16 11 148 15786 153 15786 151 11576
3/4 NL3/4" 10 258 23335 267 23335 266 17112
7/8 NL22 9 414 32195 429 32195 427 23609
1 NL1" 8 627 42228 650 42228 645 30967
1 1/8 NL30 7 784 46860 812 46860 806 34364
1 1/4 NL33 7 1091 59427 1130 59427 1127 43580
1 3/8 NL36 6 1433 70864 1485 70864 1478 51967
1 1/2 NL39 6 1880 86147 1949 86147 1949 63174

 

Cu/C paste = Copper/graphite paste 
Oil = WD40 has been used.
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient
1 lbf = 4.448 N
1 ft-lb = 1.356 Nm


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

 

      Oil, GF = 71%
μth = 0.08, μh = 0.14		 Cu/C paste, GF = 75%
μth = 0.07, μh = 0.15
Bolt Size Product Name Pitch
[TPI]		 Torque
[ftlb]		 Clamp Load
[lb]		 Torque
[ftlb]		 Clamp Load
[lb]
#5 NL3 40 1.3 748 1.3 790
#6 NL3.5 32 1.6 856 1.7 905
#8 NL4 32 2.9 1315 3.0 1389
#10 NL5 24 4.3 1651 4.6 1744
1/4 NL1/4" 20 10.0 2990 11.0 3159
5/16 NL8 18 20.0 4915 22 5192
3/8 NL3/8" 16 36 7256 38 7665
7/16 NL11 14 56 9951 60 10511
1/2 NL1/2" 13 86 13270 91 14017
9/16 NL14 12 123 16771 131 17963
5/8 NL16 11 170 21117 180 22307
3/4 NL3/4" 10 296 31214 315 32973
7/8 NL22 9 475 43067 505 45493
1 NL1" 8 718 56488 764 59671
1 1/8 NL30 7 1020 71192 1085 75203
1 1/4 NL33 7 1417 90284 1506 95370
1 3/8 NL36 6 1864 107660 1982 113725
1 1/2 NL39 6 2445 130878 2598 138251

 

Cu/C paste = Copper/graphite paste 
Oil = WD40 has been used.
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient
1 lbf = 4.448 N
1 ft-lb = 1.356 Nm


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

 

      Oil, GF = 65%
μth = 0.06, μh = 0.1		 Cu/C paste, GF = 70%
μth = 0.07, μh = 0.09
Bolt Size Product Name Pitch
[TPI]		 Torque
[ftlb]		 Clamp Load
[lb]		 Torque
[ftlb]		 Clamp Load
[lb]
#5 NL3 40 1.2 840 1.2 905
#6 NL3.5 32 1.4 962 1.5 1036
#8 NL4 32 2.5 1478 2.7 1591
#10 NL5 24 3.8 1855 4.1 1998
1/4 NL1/4" 20 8.9 3360 9.5 3618
5/16 NL8 18 18.0 5522 19.0 5947
3/8 NL3/8" 16 31 8152 33 8779
7/16 NL11 14 49 11180 52 12040
1/2 NL1/2" 13 74 14909 79 16056
9/16 NL14 12 106 19106 113 20575
5/8 NL16 11 146 23726 156 25551
3/4 NL3/4" 10 254 35071 272 37769
7/8 NL22 9 407 48388 435 52110
1 NL1" 8 614 63468 656 68350
1 1/8 NL30 7 873 79988 932 86141
1 1/4 NL33 7 1208 101439 1290 109242
1 3/8 NL36 6 1594 120691 1702 130266
1 1/2 NL39 6 2083 147048 2225 158360

 

Cu/C paste = Copper/graphite paste
Oil = WD40 has been used.
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient
1 lbf = 4.448 N
1 ft-lb = 1.356 Nm


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

 

      316ss
Cu/C paste, GF = 65%		 304ss
Cu/C paste, GF = 70%
Bolt Size Product Name Pitch
[TPI]		 Torque
[ftlb]		 Clamp Load
[lb]		 Torque
[ftlb]		 Clamp Load
[lb]
#5 NL3ss 40 0.6 342 0.7 342
#6 NL3.5ss 32 0.8 392 0.9 392
#8 NL4ss 32 1.4 602 1.5 602
#10 NL5ss 24 2.1 756 2.3 756
1/4 NL1/4”ss 20 5.1 1368 5.3 1368
5/16 NL8ss 18 10.0 2249 11.0 2249
3/8 NL3/8”ss 16 18 3320 19 3320
7/16 NL11ss 14 28 4553 30 4553
1/2 NL1/2”ss 13 43 6072 46 6072
9/16 NL14ss 12 62 7781 66 7781
5/8 NL16ss 11 85 9663 90 9663
3/4 NL3/4”ss 10 103 9884 110 9884
7/8 NL22ss 9 165 13637 176 13637
1 NL1”ss 8 250 17886 266 17886
1 1/8 NL30ss 7 355 22542 377 22542
1 1/4 NL33ss 7 494 28587 526 28587
1 3/8 NL36ss 6 649 34089 691 34089
1 1/2 NL39ss 6 853 41441 909 41441

 

Cu/C paste = Copper/graphite paste 
Oil = WD40 has been used.
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient
1 lbf = 4.448 N
1 ft-lb = 1.356 Nm


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

 

      316ss
Cu/C paste, GF = 65%		 304ss
Cu/C paste, GF = 70%
Bolt Size Product Name Pitch
[TPI]		 Torque
[ftlb]		 Clamp Load
[lb]		 Torque
[ftlb]		 Clamp Load
[lb]
#5 NL3ss-254 40 0.6 342 0.7 342
#6 NL3.5ss-254 32 0.8 392 0.9 392
#8 NL4ss-254 32 1.4 602 1.5 602
#10 NL5ss-254 24 2.1 756 2.3 756
1/4 NL1/4”ss-254 20 5.1 1368 5.3 1368
5/16 NL8ss-254 18 10.0 2249 11.0 2249
3/8 NL3/8”ss-254 16 18 3320 19 3320
7/16 NL11ss-254 14 28 4553 30 4553
1/2 NL1/2”ss-254 13 43 6072 46 6072
9/16 NL14ss-254 12 62 7781 66 7781
5/8 NL16ss-254 11 85 9663 90 9663
3/4 NL3/4”ss-254 10 103 9884 110 9884
7/8 NL22ss-254 9 165 13637 176 13637
1 NL1”ss-254 8 250 17886 266 17886
1 1/8 NL30ss-254 7 355 22542 377 22542
1 1/4 NL33ss-254 7 494 28587 526 28587
1 3/8 NL36ss-254 6 649 34089 691 34089
1 1/2 NL39ss-254 6 853 41441 909 41441

 

Cu/C paste = Copper/graphite paste 
Oil = WD40 has been used.
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient
1 lbf = 4.448 N
1 ft-lb = 1.356 Nm


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

 

      Oil, GF = 75%
μth = 0.08, μh = 0.18		 Cu/C paste, GF = 75%
μth = 0.08, μh = 0.19		 Dry, GF = 55%
μth = 0.19, μh = 0.2
Bolt Size Product Name Pitch
[TPI]		 Torque
[ftlb]		 Clamp Load
[lb]		 Torque
[ftlb]		 Clamp Load
[lb]		 Torque
[ftlb]		 Clamp Load
[lb]
5/16 NLX8 18 18 3674 18 3674 18 2694
3/8 NLX3/8" 16 31 5424 32 5424 31 3978
1/2 NLX1/2" 13 75 9920 77 9920 76 7271
9/16 NLX14 12 107 12712 111 12712 109 9322
5/8 NLX16 11 148 15786 153 15786 151 11576
3/4 NLX3/4" 10 258 23335 267 23335 266 17112

 

Cu/C paste = Copper/graphite paste 
Oil = WD40 has been used.
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

 

      Oil, GF = 71%
μth = 0.08, μh = 0.14		 Cu/C paste, GF = 75%
μth = 0.07, μh = 0.15
Bolt Size Product Name Pitch
[TPI]		 Torque
[ftlb]		 Clamp Load
[lb]		 Torque
[ftlb]		 Clamp Load
[lb]
5/16 NLX8 18 20.0 4915 22 5192
3/8 NLX3/8" 16 36 7256 38 7665
1/2 NLX1/2" 13 86 13270 91 14017
9/16 NLX14 12 123 16771 131 17963
5/8 NLX16 11 170 21117 180 22307
3/4 NLX3/4" 10 296 31214 315 32973

 

Cu/C paste = Copper/graphite paste
Oil = WD40 has been used.
GF = Ratio of yield point. When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point.
μth = Thread friction coefficient
μh = Under head friction coefficient


Thread friction coefficients have theoretical values but are verified through testing.
Under head friction coefficients have been established by tests.

Torque Guidelines Steel Construction Washers

Note that the torque guidelines below only apply to HV bolts with NLSC washers.

Washer
size

 

Reduced preload force
F *
[kN]

Modified torque method Torque 
M
[Nm]

 

Modified combined
method [torque + angle]
Pre-torque
M *
[Nm]

Securing
effect
Minimum torque
M

[Nm]
NL12SC 45 130   100 80
NL16SC 90 330   250 200
NL20SC 145 660   490 360
NL22SC 170 850   640 520
NL24SC 200 1100   825 640
NL27SC 260 1600   1220 1000
NL30SC 315 2150   1650 1320
NL36SC 460 3750   2800 2240
   

*Tightening conditions are specified in ETA-13/0246 for HV bolts, grade 10.9.

Required angle of further rotation

Clamp length angle part tum
t < 2d 45° 1/8
2d ≤ t < 6d 60° 1/6
6d ≤ t ≤ 10d 90° 1/4
10d < t No recommendations
Tightening angles when using the combined method varies depending on the clamp length, (t), in relation to bolt diameter, (d).

Frequently asked questions

How do you calculate using Kellerman&Klein?

Nord-Lock is using the Kellerman & Klein formula to calculate the relationship between torque and preload. It uses average values of the friction coefficients. Nord-Lock has added a tightening ratio to the Kellerman & Klein formula. This ratio is based on our long experience of securing bolted joints and should be viewed as a security margin. It is set to minimize the risk of overstretching the bolt while at the same time making sure the clamp load is enough to get wedge-locking effect.

Formula: T0= F0×(0,159×P+0,583×d2×μT+rm×μH) [Nm]

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What is the tightening ratio, GF?

When tightening according to guidelines and with no deviation, this is the pre-stress achieved expressed as % of yield point. The tightening ratio in this app can be set between 0 to 100%. Too low clamp load may lead to sliding or separation of parts. Too high clamp load may lead to deformation of parts or overstretched bolts. Torsion, variation in friction, scatter for the tightening tool and maximum acceptable tensile stress levels need to be considered when deciding tightening ratio.

 

How do you calculate using VDI 2230?

VDI 2230 is using the same Kellerman&Klein formula but is using minimum values of the friction coefficients and is calculating a torque corresponding to a clamp load utilizing 90% of the yield point of the bolt. The calculation consider both tensile and torsional stress. The calculation does not take into account deviations during tightening.

Which calculation standard should I use?

If you do not know which one to use, we recommend you to use Kellerman&Klein. These guidelines have been used successfully in more than 35 years and are working well together with our washers. VDI2230 becomes more and more common in the world but has been used in some European countries for a long time. If you feel insecure, you can always contact us for a deeper analysis.

 

What friction values have you used when choosing oil?

If you save the calculation you will see a summary and then it is written what values we have used in the calculation. If you do not think they are representative of your bolted connection. Make another calculation and choose custom, to fill in your own values.

 

What is the tool accuracy?

No matter what tightening tool you are using, there will always be a scatter. Tool accuracy for common tools, according to NF E 25030-1:

Digital torque wrench: ± 10%

Electronic gun with reaction arm: ± 10%

Pneumatic tool with auto air-stop: ± 20%

Calibrated torque wrench: ± 15%

Impact wrench: ±50%

What thread pitch have you been using?

When you save the calculation you will see what thread pitch has been used.

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