DOC AIRBUS | AMM A320FReplacement of Key-Locked Inserts [CFML]
TASK 70-28-00-300-801-A
Replacement of Key-Locked Inserts
Self explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
B. Consumable Materials
C. Work Zones and Access Panels
D. Referenced Information
3. Job Set-up
Subtask 70-28-00-860-056-A
Subtask 70-28-00-350-050-A
(a) Identify the defective key-locked inserts.
(b) Remove the keys by applying one of the two following procedures:
a Grind the keyway areas on the insert tapping to disengage the keys inward.
3 (c) (d) Clean the work piece tapping to remove all the foreign particles or tapping residue with acetone (Material No.CP1039) or isopropyl alcohol (Material No.CP1041) and dry.
(2) Check the tapping and the keyways.
(a)
(b) Rework the lead-in chamfer.
(c) Retap using a standard tap.
(4) Install a new insert.
1 The tappings must be clean and free from tears and foreign particles.
2 The insert threads and keys must be clean and free from burrs, roughness and other visible surface defects.
(b) Install the new insert as follows:
a b Line up the keys with the keyways of the previous insert.
c If not, replace it by another insert until the tolerance requirement is met.
d Press the keys down below to the depth specified in
2 Oversize insert:
a Until the keys come against the tapping.
bSubtask 70-28-00-280-050-A
[Rev.10 from 2021]
2026.04.01 02:20:58 UTC
Replacement of Key-Locked Inserts
WARNING:
BE CAREFUL WHEN YOU DO WORK ON THE ENGINE PARTS AFTER THE ENGINE SHUTDOWN. USE APPLICABLE THERMAL GLOVES. THE ENGINE PARTS CAN STAY HOT FOR ONE HOUR AFTER SHUTDOWN AND CAN BURN YOU.
WARNING:
YOU MUST NOT TOUCH HOT PARTS WITHOUT APPLICABLE GLOVES. HOT PARTS CAN CAUSE AN INJURY.
WARNING:
BE CAREFUL WHEN YOU USE CONSUMABLE MATERIALS. OBEY THE MATERIAL MANUFACTURER'S INSTRUCTIONS AND YOUR LOCAL REGULATIONS.
ZONE: 400
1. Reason for the JobSelf explanatory
2. Job Set-up Information
A. Fixtures, Tools, Test and Support Equipment
| REFERENCE | QTY | DESIGNATION |
|---|---|---|
| No specific | 1 | THD1032L-INSTALLATION TOOL |
| No specific | 1 | THD428L-INSTALLATION TOOL |
| No specific | 1 | THD524L-INSTALLATION TOOL |
| No specific | 1 | THD624L-INSTALLATION TOOL |
| TD428L | 1 | THREADED MANDRIL TOOL |
| TD524L | 1 | INSTALLATION TOOL |
| THXHD1032L | 1 | OVERSIZE INSTALLATION TOOL |
| THXHD428L | 1 | OVERSIZE INSTALLATION TOOL |
| THXHD524L | 1 | OVERSIZE INSTALLATION TOOL |
| THXHD624L | 1 | OVERSIZE INSTALLATION TOOL |
| REFERENCE | DESIGNATION |
|---|---|
| (Material No.CP1039) | acetone |
| (Material No.CP1041) | isopropyl alcohol |
| (Material No.CP2255) | hylomar SQ32 hylomar PL32 aerograde |
| (Material No.CP2442) | engine oil |
| No specific | MS51830 |
| No specific | MS51831 |
| No specific | MS51832 |
| ZONE/ACCESS | ZONE DESCRIPTION |
|---|---|
| 400 | POWER PLANT, NACELLES AND PYLONS |
| REFERENCE | DESIGNATION |
|---|---|
Key-Locked Insert ExtractionSubtask 70-28-00-860-056-A
A. General
(1) This task defines the procedure and provides data for the replacement of key-locked inserts.
(2) The key-locked inserts are used to lock screws in any material. The locking feature of the insert depends on the material. Low temperature inserts can have a plastic locking device while high-temperature inserts generally have a crimped feature or ovalized part of the thread to provide locking ability.
(3) The rotation of the insert inside the tapping is prevented by driving keys down into keyways broached in the insert and the workpiece at the insert upper section. In aluminum alloys, it is the keys themselves which broach the keyways as they are driven into the material of the workpiece.
(4) Depending on the insert diameter of J1466, J1326, J970 and J971 either two or four keys are used as follows:
(a) Two keys on the inserts with an inner diameter of less than 0.312 in. (7.92 mm)
(b) Four keys on the inserts with an inner diameter equal to or more than 0.312 in. (7.92 mm).
(5) Depending on the insert diameter of MS51830 and MS51831, either two or four keys are used as follows:
(a) Two keys on the inserts with an inner diameter equal to or less than 0.250 in. (6.35 mm)
(b) Four keys on the inserts with an inner diameter equal to or more than 0.312 in. (7.92 mm).
(6) Depending on the insert diameter of MS51832, either two or four keys are used as follows:
(a) Two keys on the inserts with an inner diameter equal to or less than 0.190 in. (4.83 mm)
(b) Four keys on the inserts with an inner diameter equal to or more than 0.250 in. (6.35 mm).
4. Procedure(1) This task defines the procedure and provides data for the replacement of key-locked inserts.
(2) The key-locked inserts are used to lock screws in any material. The locking feature of the insert depends on the material. Low temperature inserts can have a plastic locking device while high-temperature inserts generally have a crimped feature or ovalized part of the thread to provide locking ability.
(3) The rotation of the insert inside the tapping is prevented by driving keys down into keyways broached in the insert and the workpiece at the insert upper section. In aluminum alloys, it is the keys themselves which broach the keyways as they are driven into the material of the workpiece.
(4) Depending on the insert diameter of J1466, J1326, J970 and J971 either two or four keys are used as follows:
(a) Two keys on the inserts with an inner diameter of less than 0.312 in. (7.92 mm)
(b) Four keys on the inserts with an inner diameter equal to or more than 0.312 in. (7.92 mm).
(5) Depending on the insert diameter of MS51830 and MS51831, either two or four keys are used as follows:
(a) Two keys on the inserts with an inner diameter equal to or less than 0.250 in. (6.35 mm)
(b) Four keys on the inserts with an inner diameter equal to or more than 0.312 in. (7.92 mm).
(6) Depending on the insert diameter of MS51832, either two or four keys are used as follows:
(a) Two keys on the inserts with an inner diameter equal to or less than 0.190 in. (4.83 mm)
(b) Four keys on the inserts with an inner diameter equal to or more than 0.250 in. (6.35 mm).
Subtask 70-28-00-350-050-A
CAUTION:
DO NOT USE HYLOMAR SQ32/HYLOMAR PL32 AEROGRADE (CP2255) ON TITANIUM AND TITANIUM ALLOYS.
A. Replacement of Key-Locked Inserts NOTE: Inserts from different series are not interchangeable with one another unless called out in the IPC. Check the IPC for permitted replacement of key-locked inserts for oversize inserts if tappings are no longer fit for original inserts installation. Oversize replacements may not be available for every location or application.
(1) Remove the defective key-locked inserts.(a) Identify the defective key-locked inserts.
(b) Remove the keys by applying one of the two following procedures:
CAUTION:
BE CAREFUL WHEN YOU DRILL OR GRIND THE PART. IF YOU ARE NOT CAREFUL, THERE IS A RISK THAT:
1 Drilling: - YOU WILL CAUSE MORE DAMAGE TO THE PART THAN THE REPAIRABLE LIMITS AND
- OVERSIZE INSERTS WILL NOT BE AVAILABLE FOR REPLACEMENT.
NOTE: Since it is not always possible to determine whether the existing key-locked insert is original or oversized, drilling may be performed in two steps.
a b 2 Grinding: a Grind the keyway areas on the insert tapping to disengage the keys inward.
3 (c) (d) Clean the work piece tapping to remove all the foreign particles or tapping residue with acetone (Material No.CP1039) or isopropyl alcohol (Material No.CP1041) and dry.
(2) Check the tapping and the keyways.
(a)
NOTE: If the dimension check is not satisfactory, prepare for installation of an oversize insert.
(b) In case of slight damage, restore the tapping using the same tap. NOTE: The tappings have unified threads, class 2B, except for the modified internal thread diameter. The tapping is performed with standard taps.
(c) Visually check the keyways for impacts, burrs or any other visible damage. NOTE: In case of serious damage and only for inserts with two keys, broach two keyways at 90 degrees to the existing ones.
(3) (a) Drill the guide hole. (b) Rework the lead-in chamfer.
(c) Retap using a standard tap.
(4) Install a new insert.
NOTE: If the TD428L THREADED MANDRIL TOOL or TD524L INSTALLATION TOOL or Standard Tool TD624L - INSTALLATION TOOL or THD1032L-INSTALLATION TOOL or THD428L-INSTALLATION TOOL or THD524L-INSTALLATION TOOL or THD624L-INSTALLATION TOOL or THXHD1032L OVERSIZE INSTALLATION TOOL or THXHD428L OVERSIZE INSTALLATION TOOL is not available, the inserts can be installed with your hand and the keys driven with a soft faced punch.
(a) Check the parts before installation.1 The tappings must be clean and free from tears and foreign particles.
2 The insert threads and keys must be clean and free from burrs, roughness and other visible surface defects.
(b) Install the new insert as follows:
NOTE: Before installation, coat the external threads and tapped hole with the product hylomar SQ32 hylomar PL32 aerograde (Material No.CP2255) or engine oil (Material No.CP2442) . After installation, remove excess product. J1466 and J1326 series inserts are coated in dry film lubricant and can be installed without any additional product. However, engine oil (Material No.CP2442) can be used to aid installation.
1 Original size insert:a b Line up the keys with the keyways of the previous insert.
c If not, replace it by another insert until the tolerance requirement is met.
d Press the keys down below to the depth specified in
2 Oversize insert:
a Until the keys come against the tapping.
b
B. Inspection/Check of the Key-Locked Inserts
(1) (2) (3) After the installation of the insert, check the work piece surface for absence of raised metal beads, incipient cracks or any other defect.
(1) (2) (3) After the installation of the insert, check the work piece surface for absence of raised metal beads, incipient cracks or any other defect.