Preliminary Requirements

Procedure

1. SUBTASK 70-35-04-350-001 Remove Damage Caused by Nut Lock Procedure

   1. Hold the rim of the cupwasher on a mandrel (which can be made locally of equivalent diameter material to the nut it will lock), then lightly hammer out nut lock damage caused before. Make sure the nut lock position used before shows.

2. SUBTASK 70-35-04-240-001 Inspect the Cupwasher for Cracks

   1. Magnetically crack test the cupwasher.

      1. Refer to the SPM TASK 70-24-01-240-501, Magnetic Particle Inspection and TASK 70-20-01-200-501, Inspection of Parts (cupwasher).

3. SUBTASK 70-35-04-350-002 Remove Cracks From the Rim With a Small Scallop to the Specified Depth

   1. Scallop depth must not be more than 0.125 in. (3.17 mm) on cupwashers with a thickened section between the lock rim and the backplate. Cupwashers with an equal rim thickness must not be scalloped more than 50 percent of the rim depth.

      1. No two scallops can be nearer than 2 in. (50.8 mm) or one sixth of the rim circumference.

      2. After scalloping of the cupwasher there must be two opposite lengths of arc that are not damaged. These arcs must not be less than 2in. (50.8 mm) in length or less than one sixth of the rim circumference.

      3. Remove all of the sharp edges from the scallop to make it smooth. Refer to Figure.

4. SUBTASK 70-35-40-240-002 Examine the Cupwasher for Cracks After Small Scallop

   1. For magnetic materials, magnetically crack test the cupwasher.

      1. Refer to the SPM TASK 70-24-01-240-501, Magnetic Particle Inspection and 70-20-01-200-501, Inspection of Parts (cupwashers).

   2. For non-magnetic materials, fluorescent pentrant crack test the cupwasher.

      1. Refer to the SPM TASK 70-23-01-230-501, Fuorescent Penetrant Inspection and SPM TASK 70-20-01-200-501, Inspection of Parts (cupwasher).

5. SUBTASK 70-35-04-350-003 Remove Cracks From the Rim With a Large Scallop to the Specified Depth

   1. On cupwashers with a thickened section between the rim and the backplate, the scallop must not go further than the thickened section of the cupwasher. Cupwashers with an equal rim thickness must not be scalloped more than two thirds of the rim depth.

      1. No two scallops can be nearer than 4 in. (101.6 mm) or one third of the rim circumference.

      2. After scalloping of the cupwasher there must be two opposite lengths of arc that are not damaged. These arcs must not be less than 4in. (101.6 mm) in length or less than one third of the rim circumference.

      3. Remove all of the sharp edges from the scallop to make it smooth. Refer to Figure.

6. SUBTASK 70-35-04-240-003 Examine the Cupwasher for Cracks After Large Scallop

   1. For magnetic materials, magnetically crack test the cupwasher.

      1. Refer to the SPM TASK 70-24-01-240-501, Magnetic Particle Inspection and TASK 70-20-01-200-501, Inspection of Parts (cupwashers).

   2. For non-magnetic materials, fluorescent pentrant crack test the cupwasher.

      1. Refer to the SPM TASK 70-23-01-230-501, Fuorescent Penetrant Inspection and SPM TASK 70-20-01-200-501, Inspection of Parts (cupwasher).

7. SUBTASK 70-35-04-350-004 Install and Lock the Cupwasher

   NOTE

   If the nut has lock scallops to lock the cupwasher in (not in opposite positions) they must be used.

   1. Lock the cupwasher in the castellations in two opposite positions to the ones used before (and no nearer to a cupwasher repair scallop than a distance the same as the length of the repair scallop). Make sure the rim of the cupwasher does not cut, extend or crack.

Figure: Repair cupwasher with a scallop

Repair cupwasher with a scallop