The Screw,close Tolerance, cataloged under National Stock Number 5305-01-284-1391, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Sps Technologies, Llc Dba PB Fasteners. Government technical data includes 22 specifications, cited from the U.S. Government catalog. The record lists 5 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 8 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-284-1391 |
| Primary Part Number | 121557-4-A7P |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Sps Technologies, Llc Dba PB Fasteners |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES THREADS |
| Surface Finish | 32.0 MICROINCHES GRIP |
| Surface Finish | 32.0 MICROINCHES BEARING SURFACE OF HEAD |
| Fastener Length | 0.793 INCHES MINIMUM AND 0.823 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416 TY 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.345 INCHES MINIMUM AND 0.395 INCHES MAXIMUM IN |
| Hardness Rating | 46.0 ROCKWELL C MINIMUM AND 49.0 ROCKWELL C MAXIMUM OVERALL |
| Material Document and Classification | AMS 6487 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Grip Length | 0.428 INCHES MINIMUM AND 0.448 INCHES MAXIMUM IN |
| Grip Diameter | 0.2485 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Minimum Tensile Strength | 220000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | OFFSET CRUCIFORM (TORQUE SET) |
| Countersink Angle | 99.0 DEGREES MINIMUM AND 101.0 DEGREES MAXIMUM |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL COMP H11 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.447 INCHES MINIMUM AND 0.507 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 |
|---|---|
| 121557-4-A7P PRIMARY | Sps Technologies, Llc Dba PB Fasteners (USA) |
| H044-4-7 PRIMARY | Huck International, Inc (USA) |
| PBF1165-4-7 PRIMARY | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| VT1693F4-7 PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| AIC984-4-7 PRIMARY | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| Reference | Meaning |
|---|---|
| C7984-4-7 | 7/2 Vendor item drawing reference U.S. Government activity |
| 5305PL0884188 | 6/9 Informative reference only Jednolity Indeks Materialowy - Uniform Material Index |
| C7984-4-7 | 5/9 Secondary reference Sps Technologies Llc Dba PB Fasteners Div PB Fasteners |
| 121557-4-A7P | 3/2 Design control — primary reference U.S. Government activity |
| C7984-4-7 | 5/9 Secondary reference U.S. Government activity |
| C7984-4-7 | 5/9 Secondary reference Sps Technologies, Llc Dba PB Fasteners |
| C7984-4-7 | 5/9 Secondary reference Howmet Global Fastening Systems Inc |
| VT1693F4-7 | 5/2 Secondary reference U.S. Government activity |
NSN 5305-01-284-1391 is a Screw,close Tolerance, manufactured by Sps Technologies, Llc Dba PB Fasteners, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-284-1391 has 5 manufacturer part numbers on file: 121557-4-A7P (Sps Technologies, Llc Dba PB Fasteners), H044-4-7 (Huck International, Inc), PBF1165-4-7 (Sps Technologies Llc Dba PB Fasteners Div PB Fasteners), VT1693F4-7 (Howmet Global Fastening Systems Inc), AIC984-4-7 (Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company).
Key specifications for 121557-4-A7P: Surface Finish: 32.0 MICROINCHES THREADS; Surface Finish: 32.0 MICROINCHES GRIP; Surface Finish: 32.0 MICROINCHES BEARING SURFACE OF HEAD; Fastener Length: 0.793 INCHES MINIMUM AND 0.823 INCHES MAXIMUM IN. 22 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.