The Screw,cap,socket Head, cataloged under National Stock Number 5305-01-384-0997, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. Government technical data includes 20 specifications, cited from the U.S. Government catalog. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 5305-01-384-0997 |
| Item Name | Screw,cap,socket Head |
| FSC / FSG | 5305 / 53 — Screws |
| Status | ACTIVE |
| Width Across Flats | 0.250 INCHES NOMINAL IN |
| Head Height | 0.306 INCHES MINIMUM AND 0.312 INCHES MAXIMUM IN |
| Fastener Length | 0.312 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | MIL-C-13924 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.201 INCHES MINIMUM AND 0.312 INCHES MAXIMUM IN |
| Hardness Rating | 39.0 ROCKWELL C MINIMUM AND 45.0 ROCKWELL C MAXIMUM OVERALL |
| Material Document and Classification | QQ-N-281 CLA FED SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.312 INCHES IN |
| Head Style | FLAT CHAMFER |
| Thread Direction | RIGHT-HAND |
| Color | BLACK OVERALL |
| Surface Treatment | OXIDE OVERALL |
| Minimum Tensile Strength | 180000 POUNDS PER SQUARE INCH LBS |
| Minimum Yield Strength | 155000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HEXAGON |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 18 |
| Material | NICKEL ALLOY 400 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL COARSE (UNC) |
| Head Diameter | 0.457 INCHES MINIMUM AND 0.469 INCHES MAXIMUM IN |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Reference | Meaning |
|---|---|
| FFS86TY6,.3125- 18UNC3AX1IN, | C/1 Advisory reference — outside the item-of-supply concept Zf Industrieantriebe Witten Gmbh |
| 5/16-18UNC3AX1 IN.LG. NICU | 3/1 Design control — primary reference U.S. Government activity |
| FF-S-86/ TY6 | 4/1 Identification reference U.S. Government activity |
NSN 5305-01-384-0997 is a Screw,cap,socket Head, classified under FSC 5305, Screws. Status: active.
2 possible matches (shared part number, not a government interchangeability claim): 5305-01-471-6147, 5305-01-714-0106. Verify interchangeability with system specifications before substitution.
Key specifications for 5305-01-384-0997: Width Across Flats: 0.250 INCHES NOMINAL IN; Head Height: 0.306 INCHES MINIMUM AND 0.312 INCHES MAXIMUM IN; Fastener Length: 0.312 INCHES NOMINAL IN; Surface Treatment Document and Classification: MIL-C-13924 MIL SPEC SINGLE TREATMENT RESPONSE OVERALL. 20 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.