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ARP Torque Specifications
Listed are the recommended torque values for most ARP fasteners.
Recommended torque is equal to 75% of the fastener’s yield strength.
THE TORQUE VALUES REPRESENTED HERE ARE INTENDED TO BE FOR GENERAL INFORMATION, NOT FOR SPECIFIC INSTALLATIONS!
In special instances, where supplied instructions deviate from the torque values recommended, always follow the instructions. Simply read down to the correct fastener size, and then cross to find the torque value for your application.
Stud torque values are based on the coarse thread yield strength and torque being applied to the fine thread i.e. (7/16-14 into the block and torque applied to 7/16-20 threaded nut).
NOTE: ALWAYS LUBRICATE FASTENERS PRIOR TO APPLYING TORQUE TO ENSURE ACCURATE READINGS.
Recommended Torque to Achieve Optimum Preload (Clamping Force)
Using ARP Moly Assembly Lubricant or 30-wt. oil - Torque (ft./lbs.) - Preload (lbs.)
Note: For those using Newton/meters as a torquing reference, you must multiply the appropriate ft. /lbs. factor by 1.356.
Fastener Tensile Strength (PSI) 170,000/180,000 (1,171N/mm2)
| Thread Size and Type | Torque w/ 30wt. oil
(not recommended) |
Torque w/ ARP Moly | Preload |
| 1/4" stud |
12 |
10 |
3,804 |
| 1/4-20 |
13 |
10 |
3,804 |
| 1/4-28 |
14 |
11 |
4,344 |
| 5/16" stud |
25 |
20 |
6,264 |
| 5/16-18 |
26 |
21 |
6,264 |
| 5/16-24 |
28 |
22 |
6,948 |
| 3/8" stud |
45 |
35 |
9,276 |
| 3/8-16 |
46 | 36 |
9,276 |
| 3/8-24 |
50 |
39 |
10,512 |
| 7/16" stud |
71 |
56 |
12,720 |
| 7/16-14 |
73 |
58 |
12,720 |
| 7/16-20 |
80 |
62 |
14,220 |
| 1/2" stud |
108 |
84 |
16,992 |
| 1/2-13 |
111 |
88 |
16,992 |
| 1/2-20 |
122 |
95 |
19,164 |
| 9/16" stud |
156 |
122 |
21,792 |
| 9/16-12 |
159 |
126 |
21,792 |
| 9/16-18 |
174 |
136 |
24,312 |
| 5/8" stud |
214 |
167 |
27,072 |
| 5/8-11 |
220 |
174 |
27,072 |
| 5/8-18 |
243 |
189 |
30,660 |
| 6mm stud |
10 |
9 |
2,900 |
| 6mm x 1.0 |
11 |
9 |
2,900 |
| 8mm stud |
25 |
20 |
6,250 |
| 8mm x 1.25 |
25 |
20 |
6,250 |
| 10mm stud |
54 |
42 |
10,600 |
| 10mm x 1.25 |
54 |
42 |
10,600 |
| 10mm x 1.50 |
50 |
38 |
9,500 |
| 11mm stud |
80 |
63 |
14,220 |
| 12mm stud |
97 |
77 |
15,540 |
Fastener Tensile Strength (PSI) 190,000/200,000 (1,309 N/mm2)
| Thread Size and Type |
Torque w/ 30wt. oil
(not recommended) |
Torque w/ ARP Moly |
Preload |
| 1/4" stud |
14 |
11 |
4,280 |
| 1/4-20 |
14 |
11 |
4,280 |
| 1/4-28 |
16 |
13 |
4,887 |
| 5/16" stud |
28 |
22 |
7,047 |
| 5/16-18 |
29 |
23 |
7,047 |
| 5/16-24 |
32 |
25 |
7,817 |
| 3/8" stud |
50 |
39 |
10,436 |
| 3/8-16 |
51 |
41 |
10,436 |
| 3/8-24 |
57 |
44 |
11,826 |
| 7/16" stud |
80 |
63 |
14,310 |
| 7/16-14 |
82 |
65 |
14,310 |
| 7/16-20 |
90 |
70 |
15,998 |
| 1/2" stud |
122 |
95 |
19,116 |
| 1/2-13 |
125 |
99 |
19,116 |
| 1/2-20 |
137 |
107 |
21,560 |
| 9/16" stud |
175 |
137 |
24,516 |
| 9/16-12 |
179 |
142 |
24,516 |
| 9/16-18 |
196 |
153 |
27,351 |
| 5/8" stud |
214 |
187 |
30,456 |
| 5/8-11 |
247 |
196 |
30,456 |
| 5/8-18 |
273 |
212 |
34,493 |
| 6mm stud |
- |
- |
- |
| 6mm x 1.0 |
- |
- |
- |
| 8mm stud |
28 |
22 |
7,050 |
| 8mm x 1.25 |
25 |
20 |
7,050 |
| 10mm stud |
70 |
60 |
12,015 |
| 10mm x 1.25 |
- |
- |
- |
| 10mm x 1.50 |
- |
- |
- |
| 11mm stud |
90 |
71 |
15,998 |
| 12mm stud |
109 |
86 |
17,483 |
Fastener Tensile Strength - (PSI) 220,000 (1,515 N/mm2)
| Thread Size and Type |
Torque w/ 30wt. oil
(not recommended) |
Torque w/ ARP Moly | Preload |
| 1/4" stud |
15 |
12 |
4,755 |
| 1/4-20 |
16 |
13 |
4,755 |
| 1/4-28 |
18 |
14 |
5,430 |
| 5/16" stud |
32 |
25 |
7,830 |
| 5/16-18 |
32 |
26 |
7,830 |
| 5/16-24 |
35 |
28 |
8,685 |
| 3/8" stud |
56 |
44 |
11,595 |
| 3/8-16 |
57 |
45 |
11,595 |
| 3/8-24 |
63 |
49 |
13,140 |
| 7/16" stud |
89 |
70 |
15,900 |
| 7/16-14 |
91 |
72 |
15,900 |
| 7/16-20 |
100 |
78 |
17,775 |
| 1/2" stud |
135 |
105 |
21,240 |
| 1/2-13 |
138 |
110 |
21,240 |
| 1/2-20 |
152 |
119 |
23,955 |
| 9/16" stud |
195 |
152 |
27,240 |
| 9/16-12 |
199 |
158 |
27,240 |
| 9/16-18 |
217 |
170 |
30,390 |
| 5/8" stud |
268 |
208 |
33,840 |
| 5/8-11 |
275 |
217 |
33,840 |
| 5/8-18 |
303 |
236 |
38,325 |
| 6mm stud |
- |
- |
- |
| 6mm x 1.0 |
- |
- |
- |
| 8mm stud |
32 |
25 |
7,830 |
| 8mm x 1.25 |
- |
- |
- |
| 10mm stud |
68 |
53 |
13,350 |
| 10mm x 1.25 |
- |
- |
- |
| 10mm x 1.50 |
- |
- |
- |
| 11mm stud |
100 |
79 |
17,775 |
| 12mm stud |
122 |
96 |
19,425 |
In other types of bolted joints, this careful attention to tightening is not as important.
For example:
Flywheel bolts need only be tightened enough to prevent them from working loose. Flywheel loads are carried either by shear pins or by side loads in the bolts; they don’t cause cyclic tension loads in the bolts.
Connecting rod bolts, on the other hand, support the primary tension loads caused by engine operation and must be protected from cyclic stretching. That’s why proper tightening of connecting rod bolts is so important.
See the adjacent charts for recommended stretch and torque.
Friction is an extremely challenging problem because it is so variable and difficult to control. The best way to avoid the pitfalls of friction is by using the stretch method. This way preload is controlled and independent of friction. Each time the bolt is torqued and loosened, the friction factor gets smaller. Eventually the friction levels out and becomes constant for all following repetitions. Therefore, when installing a new bolt where the stretch method cannot be used, the bolt should be tightened and loosened several times before final torque.
The number of cycles depends on the lubricant. When using ARP® recommended lubes, five loosening and tightening cycles is enough. This will “break in” the threads sufficiently.
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