25
Publication: ZTB-080112
M-B Companies, Inc. 11/14/12
iNTRODUcTiON
fASTENER TORqUE REcOMMENDATiON
TORqUE fOR STANDARD fASTENERS
Nominal
Dia.
Threads
per inch
Tightening Torque
Tightening Torque
Tightening Torque
Tightening Torque
Lubed
Dry
Plated
Dry
Plain
Lubed
Dry
Plated
Dry
Plain
Lubed
Dry
Plated
Dry
Plain
Lubed
Dry
Plated
Dry
Plain
(in.)
K = 0.15
K = 0.17
K = 0.20
K = 0.15
K = 0.17
K = 0.20
K = 0.15
K = 0.17
K = 0.20
K = 0.15
K = 0.17
K = 0.20
Unified Coarse Thread Series
1/4
20
49 in-lbs
59 in-lbs
66 in-lbs
76 in-lbs
86 in-lbs
101 in-lbs
107 in-lbs
122 in-lbs
143 in-lbs
126 in-lbs
143 in-lbs
168 in-lbs
5/16
18
101
122
135
157
178
209
221
251
295
259
294
346
3/8
16
15 ft-lbs
18 ft-lbs
20 ft-lbs
23 ft-lbs
26 ft-lbs
31 ft-lbs
33 ft-lbs
37 ft-lbs
44 ft-lbs
38 ft-lbs
43 ft-lbs
51 ft-lbs
7/16
14
24
29
32
37
42
49
52
59
70
61
70
82
1/2
13
37
44
49
57
64
75
80
90
106
94
106
125
9/16
12
53
63
70
82
92
109
115
130
154
135
153
180
5/8
11
73
87
97
113
126
150
159
180
212
186
211
248
3/4
10
129
155
172
200
227
267
282
320
376
331
375
441
7/8
9
125
160
167
322
365
429
455
615
606
633
604
710
1
8
187
225
250
483
547
644
681
722
909
799
905
1065
1-1/8
7
266
319
354
596
675
794
966
1095
1288
1132
1283
1510
1-1/4
7
375
450
500
840
952
1121
1363
1545
1817
1597
1810
2130
1-1/2
6
652
783
869
1462
4657
1950
2371
2688
3162
2779
3150
3706
Fine Thread Series
1/4
28
56 in-lbs
68 in-lbs
75 in-lbs
87 in-lbs
99 in-lbs
116 in-lbs
123 in-lbs
139 in-lbs
164 in-lbs
144 in-lbs
163 in-lbs
192 in-lbs
5/16
24
112
135
150
174
197
231
245
278
327
287
325
383
3/8
24
17 ft-lbs
20 ft-lbs
23 ft-lbs
26 ft-lbs
30 ft-lbs
35 ft-lbs
37 ft-lbs
42 ft-lbs
49 ft-lbs
43 ft-lbs
49 ft-lbs
58 ft-lbs
7/16
20
27
32
36
41
47
55
58
66
78
68
78
91
1/2
20
41
49
55
64
72
85
90
102
120
105
120
141
9/16
18
59
71
78
91
103
121
126
146
171
151
171
201
5/8
18
82
99
110
127
144
170
180
204
240
211
239
281
3/4
16
144
173
192
223
253
297
315
357
420
369
418
492
7/8
14
138
165
184
355
403
474
502
568
669
588
666
784
1
14
210
252
280
542
614
722
765
867
1020
896
1016
1195
1-1/8
12
298
357
397
668
757
890
1083
1227
1444
1269
1439
1693
1-1/4
12
415
493
553
930
1055
1241
1509
1710
2012
1768
2004
2358
1-1/2
12
734
880
978
1645
1865
2194
2668
3024
3557
3127
3544
4169
Torque values for 1/4 and 5/16-in series are in inch -pounds. All other torque values are in foot-pounds
Torque values calculated from formulas T=KDF, where
K = 0.15 for “lubricated” conditions
K = 0.17 for zinc plated and dry conditions
K = 0.20 for plain and dry conditions
D = Nominal Diameter
F = Clamp Load
Grade 2
Grade 5
Grade 8
F N L
G9
Grade 9
Summary of Contents for ZTB
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