The Nut,self-Locking,castellated,hex, cataloged under National Stock Number 5310-00-488-4337, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Esna, Llc. Government technical data includes 12 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-00-488-4337 |
| Primary Part Number | Z8576-048K |
| Item Name | Nut,self-Locking,castellated,hex |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Esna, Llc |
| Status | ACTIVE |
| Width Across Flats | 0.430 INCHES MINIMUM AND 0.439 INCHES MAXIMUM IN |
| Thread Series | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Material Document and Classification | AMS 5735 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.250 INCHES IN |
| Locking Feature | FREE-RUNNING ALL METAL DESIGN |
| Nut Height | 0.315 INCHES MINIMUM AND 0.330 INCHES MAXIMUM IN |
| Nut Style | CASTELLATED, HEXAGON |
| Thread Class | 3BG |
| Thread Quantity Per Inch | 28 |
| Material | IRON ALLOY 660 OVERALL |
| Bearing Surface Type | CHAMFERED |
| 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 |
|---|---|
| 536775 | Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney (USA) |
| Z8576-048K PRIMARY | Esna, Llc (USA) |
| Reference | Meaning |
|---|---|
| Z8576-048K | 3/9 Design control — primary reference Harvard Industries Inc |
| 536775 | 5/9 Secondary reference Turbo Power & Marine System Inc Sub of United Technologies Corp |
| 536775 | 5/9 Secondary reference Harvard Industries Inc |
NSN 5310-00-488-4337 is a Nut,self-Locking,castellated,hex, manufactured by Esna, Llc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-488-4337 has 2 manufacturer part numbers on file: 536775 (Rtx Corporation Dba Pratt & Whitney Div Pratt &whitney), Z8576-048K (Esna, Llc).
Key specifications for Z8576-048K: Width Across Flats: 0.430 INCHES MINIMUM AND 0.439 INCHES MAXIMUM IN; Thread Series: UNIFIED NATIONAL JOINT FINE (UNJF); Material Document and Classification: AMS 5735 ASSN STD SINGLE MATERIAL RESPONSE OVERALL; Thread Direction: RIGHT-HAND. 12 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.