The Screw,cap,hexagon Head, cataloged under National Stock Number 5305-01-175-9271, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is The American Society of Mechanical Engineers. Government technical data includes 20 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-175-9271 |
| Primary Part Number | B1821BH050F125L |
| Item Name | Screw,cap,hexagon Head |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | The American Society of Mechanical Engineers |
| Status | ACTIVE |
| Head Height | 0.302 INCHES MINIMUM AND 0.323 INCHES MAXIMUM IN |
| Fastener Length | 1.188 INCHES MINIMUM AND 1.250 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | ASTM B633 TY 2 SC 3 ASSN STD SINGLE TREATMENT RESPONSE FASTENER |
| Thread Length | 1.063 INCHES MINIMUM AND 1.250 INCHES MAXIMUM IN |
| Hardness Rating | 32.0 ROCKWELL C MINIMUM AND 38.0 ROCKWELL C MAXIMUM FASTENER |
| Material Document and Classification | SAE J429 GRADE 8 ASSN STD SINGLE MATERIAL RESPONSE FASTENER |
| Nominal Thread Diameter | 0.500 INCHES IN |
| Features Provided | FINISHED HEAD |
| Head Style | HEXAGON |
| Thread Direction | RIGHT-HAND |
| Width Between Flats | 0.736 INCHES MINIMUM AND 0.750 INCHES MAXIMUM IN |
| Nondefinitive Spec/std Data | 2 TYPE AND 10P STYLE AND 8 GRADE |
| Locking Feature | PATCH OR STRIP THREADS |
| Surface Treatment | ZINC AND CHROMATE FASTENER |
| Minimum Tensile Strength | 150000 POUNDS PER SQUARE INCH LBS |
| Thread Class | 2A A |
| Thread Quantity Per Inch | 20 |
| Material | PLASTIC POLYAMIDE NYLON LOCKING FEATURE |
| Material | STEEL FASTENER |
| Thread Series Designator | UNF |
| 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 |
|---|---|
| B1821BH050F125L PRIMARY | The American Society of Mechanical Engineers (USA) |
| Reference | Meaning |
|---|---|
| FF-S-85 | 4/1 Identification reference U.S. Government activity |
| MS90727-111L | 5/9 Secondary reference U.S. Government activity |
| B1821BH050F125L | 5/9 Secondary reference U.S. Government activity |
NSN 5305-01-175-9271 is a Screw,cap,hexagon Head, manufactured by The American Society of Mechanical Engineers, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-175-9271 has 1 manufacturer part number on file: B1821BH050F125L (The American Society of Mechanical Engineers).
Key specifications for B1821BH050F125L: Head Height: 0.302 INCHES MINIMUM AND 0.323 INCHES MAXIMUM IN; Fastener Length: 1.188 INCHES MINIMUM AND 1.250 INCHES MAXIMUM IN; Surface Treatment Document and Classification: ASTM B633 TY 2 SC 3 ASSN STD SINGLE TREATMENT RESPONSE FASTENER; Thread Length: 1.063 INCHES MINIMUM AND 1.250 INCHES MAXIMUM IN. 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.