This post shows tables for the torque values for API Spec 6A integral flanges using fluoropolymer coated bolts for surface applications.
Torque values shown assume undamaged bolts, clean conditions and smooth bearing surfaces.
The torque values shown in this table will apply 50% yield tension in the bolts.
Stud Diameter | 5/8″ | 3/4″ | 7/8″ | 1″ | 1-1/8″ | 1-1/4″ * | 1-3/8″ * | 1-1/2″ * | 1-5/8″ * | 1-3/4″ | 1-7/8″ |
Torque Ft. Lbs. | 68 | 118 | 188 | 279 | 401 | 553 | 739 | 962 | 1,226 | 1,534 | 1,890 |
Stud Diameter | 2″ | 2-1/4″ | 2-1/2″ | 2-5/8″ | 2-3/4″ | 3″ | 3-1/4″ | 3-3/4″ | 3-7/8″ | 4″ |
Torque Ft. Lbs. | 2.297 | 3,276 | 4,500 | 4,716 | 5,424 | 7,047 | 8,965 | 13,782 | 15,208 | 16,730 |
* | Certain API Spec. 6A flanges have stress limits that necessitate lower than normal torque values for bolts used in these flanges. Use the chart below for these flanges. |
The torque values shown in this table will apply 40,000 psi stress in the bolts.
Flange Size | 13-5/8″ 2M | 13-5/8″ 3M | 16-3/4″ 2M | 21-1/4″ 2M |
Stud Diameter | 1-1/4″ | 1-3/8″ | 1-1/2″ | 1-5/8″ |
Torque Ft. Lbs. | 421 | 563 | 733 | 934 |