The O-Ring, cataloged under National Stock Number 5331-01-521-3856, is classified within Federal Supply Class 5331 (O-ring) of the Hardware and Abrasives group. The manufacturer of record is Caterpillar Inc Div Caterpillar Defense. The record lists 2 manufacturer part numbers 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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.
| Item Name | O-Ring |
| FSC / FSG | 5331 — O-ring (FSG 53) |
| Manufacturers | Caterpillar Inc Div Caterpillar Defense (CAGE 11083); Pon Power B.v. (CAGE H0S39) |
| Parameter | Value |
|---|---|
| NSN | 5331-01-521-3856 |
| Primary Part Number | 2594598 |
| Item Name | O-Ring |
| FSC / FSG | 5331 / 53 — O-ring |
| Manufacturer | Caterpillar Inc Div Caterpillar Defense |
| Status | ACTIVE |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Part Number | Manufacturer |
|---|---|
| 2594598 PRIMARY | Caterpillar Inc Div Caterpillar Defense (USA) |
| 259-4598 | Pon Power B.v. (NLD) |
| Reference | Meaning |
|---|---|
| 8N-7174 ITEM 14 | 5/9 Secondary reference Caterpillar Inc Div Caterpillar Defense |
| 235-3548 | 5/9 Secondary reference Caterpillar Inc Div Caterpillar Defense |
NSN 5331-01-521-3856 is a O-Ring, manufactured by Caterpillar Inc Div Caterpillar Defense, classified under FSC 5331, O-ring. Status: active.
NSN 5331-01-521-3856 has 2 manufacturer part numbers on file: 2594598 (Caterpillar Inc Div Caterpillar Defense), 259-4598 (Pon Power B.v.).
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.