The Screw,close Tolerance, cataloged under National Stock Number 5305-01-534-7550, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Heartland Precision Fasteners 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-534-7550 |
| Primary Part Number | NAS8603-7 |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Heartland Precision Fasteners Inc |
| Status | ACTIVE |
| Thread Length | 0.323 INCHES NOMINAL IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Surface Treatment | CADMIUM OVERALL |
| Countersink Angle | 99.0 DEGREES MINIMUM AND 101.0 DEGREES MAXIMUM |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 32 |
| Material | STEEL COMP 4340 OR STEEL COMP 8740 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.266 INCHES MINIMUM AND 0.303 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 |
| Part Number | Manufacturer |
|---|---|
| NAS8603-7 PRIMARY | Heartland Precision Fasteners Inc (USA) |
| Reference | Meaning |
|---|---|
| NAS8603-7 | 3/2 Design control — primary reference U.S. Government activity |
NSN 5305-01-534-7550 is a Screw,close Tolerance, manufactured by Heartland Precision Fasteners Inc, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-534-7550 has 1 manufacturer part number on file: NAS8603-7 (Heartland Precision Fasteners Inc).
Key specifications for NAS8603-7: Thread Length: 0.323 INCHES NOMINAL IN; Head Style: FLAT COUNTERSUNK; Thread Direction: RIGHT-HAND; Surface Treatment: CADMIUM OVERALL. 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.