The Reducer,boss, cataloged under National Stock Number 4730-00-640-5857, 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 Sae International Dba Sae International. 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4730-00-640-5857 |
| Primary Part Number | MS21916D10-4 |
| Item Name | Reducer,boss |
| FSC / FSG | 4730 / 47 — Hose, Pipe, Tube, Lubrication, and Railing Fittings |
| Manufacturer | Sae International Dba Sae International |
| Status | ACTIVE |
| Surface Treatment Document and Classification | MIL-A-8625,TY 2,CL 2 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Connection Style | EXTERNAL SEAT FOR GASKET SEAL (BOSS) ALL ENDS |
| Nominal Overall Length | 1.438 INCHES IN |
| Criticality Code Justification | FEAT |
| Connection Type | THREADED EXTERNAL BOSS ALL ENDS |
| Material Document and Classification | QQ-A-225/6,T6 FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Operating Pressure | 3000.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS |
| Nominal Thread Size | 0.438 INCHES SECOND END IN |
| Nominal Thread Size | 0.875 INCHES FIRST END IN |
| Specification/standard Data | 96906-MS21916 GOVERNMENT STANDARD |
| Maximum Operating Temp | 225.0 FAHRENHEIT FIRST RESPONSE DEGF |
| Maximum Operating Temp | -65.0 FAHRENHEIT SECOND RESPONSE DEGF |
| Surface Treatment | ANODIZE OVERALL |
| Thread Class | 3A ALL ENDS A |
| Material | ALUMINUM ALLOY 2024 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) ALL ENDS |
| Reducer Type | CONCENTRIC |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | Y |
| Part Number | Manufacturer |
|---|---|
| MS21916D10-4 PRIMARY | Sae International Dba Sae International (USA) |
| Reference | Meaning |
|---|---|
| AS21916 | 5/9 Secondary reference U.S. Government activity |
| ER919D10-4 | 5/9 Secondary reference Dana Corp Weatherhead Div |
| MS21916D10-4 | 5/9 Secondary reference U.S. Government activity |
| AS21916 | 3/1 Design control — primary reference Sae International Dba Sae International |
| MS21916D10-4 | 5/9 Secondary reference U.S. Government activity |
NSN 4730-00-640-5857 is a Reducer,boss, manufactured by Sae International Dba Sae International, classified under FSC 4730, Hose, Pipe, Tube, Lubrication, and Railing Fittings. Status: active.
NSN 4730-00-640-5857 has 1 manufacturer part number on file: MS21916D10-4 (Sae International Dba Sae International).
Key specifications for MS21916D10-4: Surface Treatment Document and Classification: MIL-A-8625,TY 2,CL 2 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL; Connection Style: EXTERNAL SEAT FOR GASKET SEAL (BOSS) ALL ENDS; Nominal Overall Length: 1.438 INCHES IN; Criticality Code Justification: FEAT. 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.
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.