Preliminary Requirements

Safety Requirements

WARNING

IT IS THE RESPONSIBILITY OF THE OPERATOR TO OBTAIN AND OBSERVE THE MANUFACTURER'S MATERIALS SAFETY DATA SHEETS FOR CONSUMABLE MATERIALS. THESE CONTAIN INFORMATION SUCH AS, HAZARDOUS INGREDIENTS, PHYSICAL/CHEMICAL CHARACTERISTICS, FIRE, EXPLOSION, REACTIVITY, HEALTH HAZARD DATA, PRECAUTIONS FOR SAFE HANDLING, USE AND CONTROL MEASURES AND ALSO TO TAKE LOCAL REGULATIONS INTO CONSIDERATION.

Procedure

1. SUBTASK 70-46-01-400-001 Stud Torques

   1. NOTE

      The torque limits given in procedures A. and B. are for driving studs which have a minimum ultimate tensile strength of 125,000 pounds per square inch (equivalent to a minimum hardness of 26 HRC).

      Studs which have a minimum hardness of 34 HRC, the maximum torque values can be increased by 25 percent.

      Refer to Figure, Figure and Figure.

   2. Studs installed directly in to bosses.

      1. Standard interference fit studs.

         1. Use the torque limits given in Figure for driving studs where the thread sizes on each end of the stud are equal.

      2. Stepped interference fit studs.

         1. Use the torque limits given in Figure for driving studs where the thread size of the nut end is smaller than the thread size of the driven end.

      3. Stud selection.

         1. If the torque necessary to install a stud in to a boss does not get to the minimum, or is more than the maximum given in Figure and Figure, a different stud must be selected.

         2. When available 0.003 inch (0.076 mm) undersize or 0.003 inch (0.076 mm) oversize studs can be used.

      4. Burnishing studs.

         1. If necessary, burnishing studs to size the internal thread is permitted. These studs can be plain or be made with two opposite flat surfaces, at or below the minor diameter of the thread.

   3. Studs installed in to self-locking helical coil inserts.

      1. Use the torque limits given in Figure for driving studs in to self locking helical coil inserts. These limits are for studs where the nominal thread size on each end of the studs are equal. Also they are for studs where the thread size of the nut end is smaller than the thread size of the driven end.

   4. Studs driven from coarse pitch thread.

      1. Use the torque limits given in Figure or Figure, for studs which are driven from an extended coarse pitch thread or from flats adjacent to the coarse pitch thread.

   5. Studs installed in to nonlocking helical coil inserts.

      1. Use the torque limits given in Figure for driving interference fit studs in to nonlocking helical coil inserts.

2. SUBTASK 70-46-01-400-002 Stud Lubrication

   1. Oil lubricated studs.

      1. The torque values given in Figure and Figure use engine oil, SAE 250 petroleum oil or equivalent, on the threads.

   2. Antiseize lubricated studs.

   3. Interference fit titanium studs or any stud driven directly in to titanium to the torque limits given in Figure and Figure must be lubricated with wet CoMat 06-081 COMPOUND, ANTIGALLING. Oil is not permitted.

   4. Studs in self-locking helical coil inserts.

      1. Studs can be installed with or without lubrication.

         1. If lubrication is used, use CoMat 10-077 APPROVED ENGINE OILS or CoMat 10-129 ANTI-SEIZE PASTE. Refer to the SPM TASK 70-38-38-380-501. The minimum and maximum torque limits in Figure must be used.

Figure: Replacement stud types

Replacement stud types



Figure: Standard interference fit stud torque limits

Standard interference fit stud torque limits



Figure: Stepped interference fit stud torque limits

Stepped interference fit stud torque limits



Figure: Standard and stepped studs installed in self-locking helical coil inserts

Standard and stepped studs installed in self-locking helical coil inserts