The Reducer,boss, cataloged under National Stock Number 4730-00-541-4901, is classified within Federal Supply Class 4730 (Hose, Pipe, Tube, Lubrication, and Railing Fittings) of the Pipe, Tubing, Hose, and Fittings group. The manufacturer of record is Marshall of Cambridge Aerospace Limited. Government technical data includes 17 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through both NSN and commercial part number lookups. 9 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Cancelled.
| Parameter | Value |
|---|---|
| NSN | 4730-00-541-4901 |
| Primary Part Number | MS21916-6-4 |
| Item Name | Reducer,boss |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Manufacturer | Marshall of Cambridge Aerospace Limited |
| Status | CANCELLED |
| Surface Treatment Document and Classification | QQ-P-416,TYPE 2,CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Connection Style | EXTERNAL SEAT FOR GASKET SEAL (BOSS) ALL ENDS |
| Nominal Overall Length | 1.219 INCHES IN |
| Connection Type | THREADED EXTERNAL BOSS ALL ENDS |
| Material Document and Classification | QQ-A-367 FED SPEC SINGLE MATERIAL RESPONSE OR ASTM A576-677 ASSN STD SINGLE MATERIAL RESPONSE OR MIL-S-6758 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Reduced Passage Nominal Inside Diameter | 0.188 INCHES ALL ENDS IN |
| Nominal Thread Size | 0.438 INCHES SECOND END IN |
| Nominal Thread Size | 0.562 INCHES FIRST END IN |
| Specification/standard Data | 96906-MS21916 GOVERNMENT STANDARD |
| Maximum Operating Temp | 275.0 FAHRENHEIT SINGLE RESPONSE DEGF |
| Surface Treatment | CADMIUM OVERALL |
| Media for Which Designed | HYDRAULIC FLUID SINGLE RESPONSE |
| Thread Class | 3A ALL ENDS A |
| Material | STEEL COMP 1137 OR STEEL COMP 1141 OR STEEL COMP 4130 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) ALL ENDS |
| Reducer Type | CONCENTRIC |
| Acquisition Status | CANCELLED |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| MS21916-6-4 | Marshall of Cambridge Aerospace Limited (GBR) |
| Reference | Meaning |
|---|---|
| ER919-6 | 5/9 Secondary reference Dana Corp Weatherhead Div |
| ER919-6-4 | 5/9 Secondary reference Dana Corp Weatherhead Div |
| 4730-541-4901 | 5/9 Secondary reference E.c.a Etablissement Centrald'approvisionnement Des Forces Armee |
| AS21916-6-4 | 5/9 Secondary reference U.S. Government activity |
| MS21916-6-4 | 2/2 Government specification standardization U.S. Government activity |
| AS18280 | 5/9 Secondary reference U.S. Government activity |
| AS18280 | 5/1 Secondary reference Sae International Dba Sae International |
| 4730005414901 | 5/9 Secondary reference E.c.a Etablissement Centrald'approvisionnement Des Forces Armee |
| AS21916-6-4 | 5/1 Secondary reference Sae International Dba Sae International |
NSN 4730-00-541-4901 is a Reducer,boss, manufactured by Marshall of Cambridge Aerospace Limited, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: cancelled.
NSN 4730-00-541-4901 has 1 manufacturer part number on file: MS21916-6-4 (Marshall of Cambridge Aerospace Limited).
1 possible match (shared part number, not a government interchangeability claim): 4730-01-534-8659. Verify interchangeability with system specifications before substitution.
Key specifications for MS21916-6-4: Surface Treatment Document and Classification: QQ-P-416,TYPE 2,CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Connection Style: EXTERNAL SEAT FOR GASKET SEAL (BOSS) ALL ENDS; Nominal Overall Length: 1.219 INCHES IN; Connection Type: THREADED EXTERNAL BOSS ALL ENDS. 17 specifications are documented in the U.S. Government catalog.
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
NSN 4730-00-541-4901 is currently cancelled. Check with the Defense Logistics Agency for current availability and authorized substitutes.
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.