The Nut,plain,hexagon, cataloged under National Stock Number 5310-00-012-1956, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is U S Army Tank Automotive Command Amsta-Im-Mm. Government technical data includes 13 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through both NSN and commercial part number lookups. 7 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 5310-00-012-1956 |
| Primary Part Number | 121956 |
| Item Name | Nut,plain,hexagon |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | U S Army Tank Automotive Command Amsta-Im-Mm |
| Status | ACTIVE |
| Width Across Flats | 0.625 INCHES NOMINAL IN |
| Thread Series | UNF |
| Material Document and Classification | QQ-S-633-CANC FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.438 INCHES IN |
| Nondefinitive Spec/std Data | A TYPE |
| Nut Height | 0.375 INCHES NOMINAL IN |
| Surface Treatment | PHOSPHATE OVERALL |
| Nut Style | HEXAGON |
| Thread Class | 3B |
| Thread Quantity Per Inch | 20 |
| Material | STEEL OVERALL |
| Bearing Surface Type | CHAMFERED OR WASHER FACED |
| 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 |
|---|---|
| 121956 | U S Army Tank Automotive Command Amsta-Im-Mm (USA) |
| Reference | Meaning |
|---|---|
| 121956 | 3/9 Design control — primary reference General Motors Corp |
| 121956 | 5/9 Secondary reference International Harvester Co Agricultural Equipment Div |
| 121956 | C/1 Advisory reference — outside the item-of-supply concept General Motors Llc Dba General Motors Llc |
| BBTX1HA5 | 5/9 Secondary reference U S Army Tank Automotive Command Amsta-Im-Mm |
| FF-B-571 | 5/9 Secondary reference U.S. Government activity |
| 33788S2 | 5/9 Secondary reference Ford Motor Co Ford Parts and Service Div Government Part Sales |
| FF-N-836 | 4/1 Identification reference U.S. Government activity |
NSN 5310-00-012-1956 is a Nut,plain,hexagon, manufactured by U S Army Tank Automotive Command Amsta-Im-Mm, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-00-012-1956 has 1 manufacturer part number on file: 121956 (U S Army Tank Automotive Command Amsta-Im-Mm).
2 possible matches (shared part number, not a government interchangeability claim): 6625-00-594-2103, 5805-01-068-6039. Verify interchangeability with system specifications before substitution.
Key specifications for 121956: Width Across Flats: 0.625 INCHES NOMINAL IN; Thread Series: UNF; Material Document and Classification: QQ-S-633-CANC FED SPEC SINGLE MATERIAL RESPONSE OVERALL; Thread Direction: RIGHT-HAND. 13 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.