The Seat,helical Compression Spring, cataloged under National Stock Number 5340-00-781-3775, is classified within Federal Supply Class 5340 (Hardware, Commercial) of the Hardware and Abrasives group. The manufacturer of record is Northrop Grumman Systems Corporation. Government technical data includes 11 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active. Unit of issue: EA.
| Parameter | Value |
|---|---|
| NSN | 5340-00-781-3775 |
| Primary Part Number | A51G20522-11 |
| Item Name | Seat,helical Compression Spring |
| FSC / FSG | 5340 / 53 — Hardware, Commercial |
| Manufacturer | Northrop Grumman Systems Corporation |
| Status | ACTIVE |
| Countersink Angle in Deg | 45.0 |
| FSC Application Data | SPRING ASSEMBLY,CENTERING,SIDE BRACE,MAIN LANDING GEAR,AIRCRAFT |
| First Step Diameter | 0.8660 INCHES MINIMUM AND 0.8680 INCHES MAXIMUM IN |
| End Diameter | 0.4800 INCHES MINIMUM AND 0.4850 INCHES MAXIMUM IN |
| Countersink Diameter | 0.4600 INCHES NOMINAL IN |
| Distance From End to First Step | 0.5200 INCHES NOMINAL IN |
| Design Type | SOLID |
| Style Designator | SEAT |
| Test Data Document | 81349-MIL-I-6866 SPECIFICATION (INCLUDES ENGINEERING TYPE BULLETINS, BROCHURES,ETC., THAT REFLECT SPECIFICATION TYPE DATA IN SPECIFICATION FORMAT; EXCLUDES COMMERCIAL CATALOGS, INDUSTRY DIRECTORIES, AND SIMILAR TRADE PUBLICATIONS, REFLECTING GENERAL TYPE DATA ON CERTAIN ENVIRONMENTAL AND PERFORMANCE REQUIREMENTS AND TEST CONDITIONS THAT ARE SHOWN AS "TYPICAL", "AVERAGE", "NOMINAL", ETC.). |
| Bore Diameter | 0.4010 INCHES MINIMUM AND 0.4020 INCHES MAXIMUM IN |
| Material | ALUMINUM ALLOY |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | Possible hazard — SDS may be required (DLA HMIC P) |
| Criticality Code | X |
| Unit of Issue | EA |
| Part Number | Manufacturer |
|---|---|
| A51G20522-11 PRIMARY | Northrop Grumman Systems Corporation (USA) |
| Reference | Meaning |
|---|---|
| A51G20522-11 | 5/9 Secondary reference Northrop Grumman Systems Corporation |
| A51G20522-11 | 3/9 Design control — primary reference Northrop Grumman Systems Corporation Dba Northrop Grumman Systems Corp Div Northrop Grumman Aeronautics Systems |
NSN 5340-00-781-3775 is a Seat,helical Compression Spring, manufactured by Northrop Grumman Systems Corporation, classified under FSC 5340, Hardware, Commercial. Status: active.
NSN 5340-00-781-3775 has 1 manufacturer part number on file: A51G20522-11 (Northrop Grumman Systems Corporation).
Key specifications for A51G20522-11: Overall Height: 0.6000 INCHES NOMINAL IN; Countersink Angle in Deg: 45.0; FSC Application Data: SPRING ASSEMBLY,CENTERING,SIDE BRACE,MAIN LANDING GEAR,AIRCRAFT; First Step Diameter: 0.8660 INCHES MINIMUM AND 0.8680 INCHES MAXIMUM IN. 11 specifications are documented in the U.S. Government catalog.
Possible hazard — SDS may be required (DLA HMIC P). Hazard information on this page is shown exactly as it appears in the DLA record.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-16.
U.S. Government catalog: edition PUBLOGDVD v12.0.0 (OCT 2026), edition date 2026-10-01, retrieved 2026-10-18.