PWA 315 - Standard Torque Recommendations [PW11]

TASK 70-24-00-910-806-A
PWA 315 - Standard Torque Recommendations

WARNING: BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.

1. Reason for the Job
This procedure contains standard practice procedures and specifications used for the correct torquing of jet engine fasteners and hardware.

NOTE: Always obey the specific procedures and limits in the AMM maintenance task.

2. Job Set-up Information
A. Referenced Information

REFERENCE	DESIGNATION
Torques and Torque Wrenches - (Torque Adapters and Method Calculation)
Torques and Torque Wrenches - (Nuts, Bolts, Screws)

3. Job Set-up
Subtask 70-24-00-860-058-A ** ON A/C NOT FOR ALL

A. Not Applicable

4. Procedure
Subtask 70-24-00-911-053-A ** ON A/C NOT FOR ALL

A. General - Definitions

NOTE: Always obey the procedures and limits in the specific maintenance tasks of this manual. The specific maintenance tasks and limits always supersede those in this standard practices section.

(1) Breakaway Torque - The initial amount of force necessary to turn a self-locking fastener with the self-locking (friction) feature engaged. Breakaway torques can be measured with or without an axial force (load) as specified by the specific instruction.
(2) Run-On Torque - The amount of force necessary to turn a self-locking fastener with the self-locking (friction) feature engaged. Referred to as drag torque.
(3) Self-Locking Fastener - A nut or bolt that has a feature which causes a frictional resistance to turning. The amount of force to overcome this friction is referred to as run-on torque.
(4) Standard Torque - The torque necessary for sufficient attachment and pre-load of parts without stress to the parts.
(5) Torque Adapter - A device which is used to torque fasteners where straight access is not possible. The use and orientation of a torque adapter can affect the torque indication and actual torque applied.
(6) Torque Wrench - A device which indicates the force applied to a fastener. There are three types of torque wrenches (beam type, click type and digital type).

Subtask 70-24-00-911-054-A ** ON A/C NOT FOR ALL

B. General - Equipment Calibration
(1) Torque wrenches should be on a scheduled calibration program based on the frequency of use and the user's own experience. Anytime that a torque wrench is dropped or damaged, the tool must be inspected and calibrated.
(2) Inspect and calibrate all torque wrenches as follows:
(a) Do all torque wrench calibrations with a calibrated weight and measured lever arm device to make sure you get the accurate calibration.
(b) Do not compare one torque wrench with another torque wrench for accurate calibration.
(c) Always hold and use a torque wrench as specified in the manufacturer's instructions for accurate torque indications.
(d) Install a calibration label on the torque wrench with an expiration date.

Subtask 70-24-00-911-055-A ** ON A/C NOT FOR ALL

C. General - Equipment Requirements
(1) Always obey the procedures and limits in the specific procedures of this manual. The specific procedures and limits in task specific page blocks always supersede those in this standard practices page block.
(2) Use the correct size torque wrench as follows:
(a) Select the correct size torque wrench so that the specified torque is between 25 percent and 95 percent of the torque wrench maximum indication.
(b) Use the torque wrench that will have the best and most accurate indication graduations.
(3) Use a torque wrench and torque adapter (extension) as follows:
(a) There are many situations which require the use of a torque adapter. When you use a torque adapter, you must calculate the torque wrench indication so that you apply the specified torque to the fastener.
(b) When you install a torque adapter to a torque wrench, you can change the effective beam length of the torque wrench. You can install the torque adapter in three ways. When you change the effective beam length, you must calculate the torque wrench indication so that you apply the specified torque to the fastener.
1 For the installation of a torque adapter which increases the effective beam length, calculate the indicated torque value using Method A.
2 For the installation of a torque adapter which decreases the effective beam length, calculate the indicated torque value using Method B.
3 For the installation of a torque adapter which does not have an effect on the beam length, no calculation is necessary.

Subtask 70-24-00-910-058-A ** ON A/C NOT FOR ALL

D. Procedures
(1) Apply the correct lubricant, if necessary, to the fasteners as specified in this manual at specific engine locations. Wipe to remove the unwanted lubricant.
(2) Free-spinning nuts, bolts, screws and self-locking nuts on studs (also free-spinning nuts that lock after contact).
(a) When possible, turn the nut and hold the bolt.

NOTE: If it is necessary to turn the bolt, make sure that the bolt holes in the mating parts align, and that the bolt shank is not tight in the bolt hole.

(b) When it is not necessary to align locking features (lockwire holes, cotter pin holes, etc.), torque the fastener to approximately the middle of the torque range.
(c) When it is necessary to align locking features (lockwire holes, cotter pin holes, etc.), torque the fastener to the minimum torque. Check the alignment of the locking features. If necessary, turn the fastener further (within the torque limits) to align the holes. Never loosen or decrease the torque for alignment. If you cannot get the correct alignment within the torque range, you must replace the fastener with another.

CAUTION: WHEN IT IS NECESSARY TO INCREASE OR DECREASE THE TEMPERATURE OF ENGINE PARTS, DO NOT TORQUE THE FASTENERS TO THE FINAL TORQUE VALUE UNTIL AFTER THE PARTS ARE BACK TO APPROXIMATELY ROOM TEMPERATURE. IF THE PART TEMPERATURE WAS INCREASED, THE FASTENERS CAN BECOME LOOSE AFTER THE PARTS GO BACK TO ROOM TEMPERATURE. IF THE PART TEMPERATURE WAS DECREASED, THERE IS A RISK OF STRESS ON THE FASTENERS AFTER THE PARTS GO BACK TO ROOM TEMPERATURE.

(3) When it is necessary to heat or cool engine parts, torque the fasteners to the final torque value only after the parts return to approximately room temperature.

NOTE: If the parts were heated, the fasteners can become loose after the parts return to room temperature. If the parts were chilled, the fasteners can become stressed after the parts return to room temperature.

(4) Use caution when you join flanges or mating sections during assembly. When you join snap fits, it is essential that mating parts be correctly seated prior to application of final torque. Unless specific procedures are provided in assembly instructions, parts should be seated by installing several bolts at regular intervals then applying uniform torque where required to seat the mating surfaces. Once seating is assured, all bolts should be torqued to approximately 75 percent of final torque in a uniform stagger (180-, 90-, and 45-degree intervals, etc.) to prevent local over-stressing of the bolts or flange. Final torque should be applied in the same sequence.
(5) Torque applications should be done slowly and evenly for consistency and best possible accuracy.
(6) For crush or compression type gaskets and seals, torque the attaching fasteners as follows:
(a) With all the fasteners installed, torque the fasteners in an opposite torque pattern and in small increments as not to exceed the torque limits.
(b) Continue to torque the fasteners to the specified limits until the same torque indication holds on the torque wrench.

[Rev.10 from 2021] 2026.04.01 02:20:12 UTC