The Nut,plain,hexagon, cataloged under National Stock Number 5310-01-623-8495, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Naval Inventory Control Point Mechanicsburg. Government technical data includes 2 specifications, cited from the U.S. Government catalog. The record lists 4 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 6 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 3 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-623-8495 |
| Primary Part Number | 709-8540939 ITEM 21-7D4 |
| Item Name | Nut,plain,hexagon |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Naval Inventory Control Point Mechanicsburg |
| Status | ACTIVE |
| Criticality Code Justification | ZZZX |
| Departure From Cited Designator | MATERIAL CONTROLLED IAW SS800-AG-MAN-010/P-9290 SYSTEM CERTIFICATION PRODURES AND CRITERIA MANUAL FOR DEEP SUBMERGENCE SYSTEMS; CRITICAL ITEM FOR SAFETY AND SURVIVAL OF DEEP SUBMERGENCE RESEARCH AND RESCUE VEHICLES AS DIFFERENTIATED BY SPECIAL TEST FEATURES |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | S |
| Part Number | Manufacturer |
|---|---|
| 709-8540939 ITEM 21-7D4 | Naval Inventory Control Point Mechanicsburg (USA) |
| 709-8345731-002-003D4 | Naval Inventory Control Point Mechanicsburg (USA) |
| 709-8345731-006-002-002D4 | Naval Inventory Control Point Mechanicsburg (USA) |
| 709-8345731-002-009D4 | Naval Inventory Control Point Mechanicsburg (USA) |
| Reference | Meaning |
|---|---|
| 709-8345731-002-003 | 5/1 Secondary reference Naval Sea Systems Command |
| 0.500-13UNC-3B NICUD4 | 5/1 Secondary reference Naval Inventory Control Point Mechanicsburg |
| 709-8345731-006-002-002 | 5/1 Secondary reference Naval Sea Systems Command |
| 709-8540939 ITEM 21-7 | 3/1 Design control — primary reference Naval Sea Systems Command |
| 0.500-13UNC-3B NICU | 4/1 Identification reference U.S. Government activity |
| 709-8345731-002-009 | 3/1 Design control — primary reference Naval Sea Systems Command |
NSN 5310-01-623-8495 is a Nut,plain,hexagon, manufactured by Naval Inventory Control Point Mechanicsburg, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-623-8495 has 4 manufacturer part numbers on file: 709-8540939 ITEM 21-7D4 (Naval Inventory Control Point Mechanicsburg), 709-8345731-002-003D4 (Naval Inventory Control Point Mechanicsburg), 709-8345731-006-002-002D4 (Naval Inventory Control Point Mechanicsburg), 709-8345731-002-009D4 (Naval Inventory Control Point Mechanicsburg).
3 possible matches (shared part number, not a government interchangeability claim): 5310-01-640-7497, 5310-01-654-1921, 5310-01-659-1042. Verify interchangeability with system specifications before substitution.
Key specifications for 709-8540939 ITEM 21-7D4: Criticality Code Justification: ZZZX; Departure From Cited Designator: MATERIAL CONTROLLED IAW SS800-AG-MAN-010/P-9290 SYSTEM CERTIFICATION PRODURES AND CRITERIA MANUAL FOR DEEP SUBMERGENCE SYSTEMS; CRITICAL ITEM FOR SAFETY AND SURVIVAL OF DEEP SUBMERGENCE RESEARCH AND RESCUE VEHICLES AS DIFFERENTIATED BY SPECIAL TEST FEATURES; Part Name Assigned by Controlling Agency: DRY DECK SHELTER FC-156 CRADLE ASSEMBLY AND DETAILS. 2 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.