The Ring Set,piston, cataloged under National Stock Number 2990-00-554-2201, is classified within Federal Supply Class 2990 (Miscellaneous Engine Accessories, Nonaircraft) of the Engine Accessories group. The manufacturer of record is Caterpillar Inc Div Caterpillar Defense. Government technical data includes 4 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 2990-00-554-2201 |
| Primary Part Number | 9H1399 |
| Item Name | Ring Set,piston |
| FSC / FSG | 2990 / 29 — Miscellaneous Engine Accessories, Nonaircraft |
| Manufacturer | Caterpillar Inc Div Caterpillar Defense |
| Status | ACTIVE |
| Bore Diameter Oversize | 0.040 INCHES IN |
| Ring Set Component Parts | COMPRESSION RING,5B3,11083,3,OIL RING,4B9998,11083,2 |
| Piston Accommodation Quantity | 1 |
| Standard Bore Diameter | 3.125 INCHES IN |
| 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 |
|---|---|
| 9H1399 PRIMARY | Caterpillar Inc Div Caterpillar Defense (USA) |
| Reference | Meaning |
|---|---|
| IPD9H1399 | 5/9 Secondary reference Industrial Parts Depot, Llc Dba Ipd |
NSN 2990-00-554-2201 is a Ring Set,piston, manufactured by Caterpillar Inc Div Caterpillar Defense, classified under FSC 2990, Miscellaneous Engine Accessories, Nonaircraft. Status: active.
NSN 2990-00-554-2201 has 1 manufacturer part number on file: 9H1399 (Caterpillar Inc Div Caterpillar Defense).
Key specifications for 9H1399: Bore Diameter Oversize: 0.040 INCHES IN; Ring Set Component Parts: COMPRESSION RING,5B3,11083,3,OIL RING,4B9998,11083,2; Piston Accommodation Quantity: 1; Standard Bore Diameter: 3.125 INCHES IN. 4 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.