Coast High Performance | (310) 784 1010 | The Home Of Pure Horsepower












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 TypeTorque w/ 30wt. oil
(not recommended)
Torque w/ ARP MolyPreload
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 4636 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 MolyPreload
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.