The Nut,plain,cone Seat,hexagon, cataloged under National Stock Number 5310-01-388-8570, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is Isometrics Inc. 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5310-01-388-8570 |
| Primary Part Number | 277B-3-12 |
| Item Name | Nut,plain,cone Seat,hexagon |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | Isometrics Inc |
| Status | ACTIVE |
| Width Across Flats | 0.813 INCHES NOMINAL IN |
| Thread Series | UNF |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.500 INCHES IN |
| Cone Seat Angle | 60.0 DEGREES NOMINAL |
| Nut Height | 0.625 INCHES NOMINAL IN |
| Nut Style | CONE SEAT, HEXAGON |
| Thread Class | 2B |
| Thread Quantity Per Inch | 20 |
| Material | STEEL OVERALL |
| 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 |
|---|---|
| 277B-3-12 PRIMARY | Isometrics Inc (USA) |
| Reference | Meaning |
|---|---|
| 306012103 | 5/9 Secondary reference Cromwell Builders Manufacturing Inc Dba Jc.net/cromwell/builders |
| 06-12103 | 5/9 Secondary reference Cromwell Builders Manufacturing Inc Dba Jc.net/cromwell/builders |
NSN 5310-01-388-8570 is a Nut,plain,cone Seat,hexagon, manufactured by Isometrics Inc, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-388-8570 has 1 manufacturer part number on file: 277B-3-12 (Isometrics Inc).
1 possible match (shared part number, not a government interchangeability claim): 5310-01-663-0405. Verify interchangeability with system specifications before substitution.
Key specifications for 277B-3-12: Width Across Flats: 0.813 INCHES NOMINAL IN; Thread Series: UNF; Thread Direction: RIGHT-HAND; Nominal Thread Size: 0.500 INCHES IN. 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.