The Ring,wearing, cataloged under National Stock Number 4320-00-203-9455, is classified within Federal Supply Class 4320 (Power and Hand Pumps) of the Pumps and Compressors group. The manufacturer of record is Fairbanks Morse, Llc. Government technical data includes 10 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 4320-00-203-9455 |
| Primary Part Number | F21-2D16B1 |
| Item Name | Ring,wearing |
| FSC / FSG | 4320 / 43 — Power and Hand Pumps |
| Manufacturer | Fairbanks Morse, Llc |
| Status | ACTIVE |
| Surface Finish | 125.0 MICROINCHES OUTSIDE |
| Surface Finish | 125.0 MICROINCHES LEFT FACE |
| Surface Finish | 125.0 MICROINCHES INSIDE |
| Surface Finish | 125.0 MICROINCHES RIGHT FACE |
| Corner Shape | SQUARE ALL CORNERS |
| Body Style | PLAIN |
| Body Outside Diameter | 4.377 INCHES MINIMUM AND 4.379 INCHES MAXIMUM IN |
| Material Document and Classification | MIL-B-16541 MIL SPEC SINGLE MATERIAL RESPONSE |
| Body Inside Diameter | 4.002 INCHES MINIMUM AND 4.004 INCHES MAXIMUM IN |
| Material | COPPER ALLOY |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| F21-2D16B1 PRIMARY | Fairbanks Morse, Llc (USA) |
| Reference | Meaning |
|---|---|
| F21-2D16B1 | 3/9 Design control — primary reference U.S. Government activity |
NSN 4320-00-203-9455 is a Ring,wearing, manufactured by Fairbanks Morse, Llc, classified under FSC 4320, Power and Hand Pumps. Status: active.
NSN 4320-00-203-9455 has 1 manufacturer part number on file: F21-2D16B1 (Fairbanks Morse, Llc).
Key specifications for F21-2D16B1: Surface Finish: 125.0 MICROINCHES OUTSIDE; Surface Finish: 125.0 MICROINCHES LEFT FACE; Surface Finish: 125.0 MICROINCHES INSIDE; Surface Finish: 125.0 MICROINCHES RIGHT FACE. 10 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.