The Screw,close Tolerance, cataloged under National Stock Number 5305-01-044-8532, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Hi-Shear Corporation. Government technical data includes 21 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 9 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-044-8532 |
| Primary Part Number | HT239PB-4-2 |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Hi-Shear Corporation |
| Status | ACTIVE |
| Surface Finish | 63.0 MICROINCHES GRIP |
| Surface Finish | 63.0 MICROINCHES THREADS |
| Fastener Length | 0.425 INCHES MINIMUM AND 0.472 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416,TYPE 2,CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.290 INCHES MINIMUM AND 0.357 INCHES MAXIMUM IN |
| Hardness Rating | 36.0 ROCKWELL C MINIMUM AND 40.0 ROCKWELL C MAXIMUM OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 26512-GB510L PROFESSIONAL/INDUSTRIAL ASSOCIATION STANDARD |
| Grip Length | 0.115 INCHES MINIMUM AND 0.135 INCHES MAXIMUM IN |
| Grip Diameter | 0.2485 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Minimum Tensile Strength | 160000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HIGH-TORQUE |
| Countersink Angle | 100.0 DEGREES NOMINAL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL COMP 4140 OR STEEL COMP E4340 OR STEEL COMP 6150 OR STEEL COMP 8735 OR STEEL COMP 8740 OR STEEL COMP 4130 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.390 INCHES MINIMUM AND 0.395 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 |
|---|---|
| HT239PB-4-2 | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| HT239PB-4-2 PRIMARY | Hi-Shear Corporation (USA) |
| Reference | Meaning |
|---|---|
| HT8043-4-2 | 5/9 Secondary reference U.S. Government activity |
| GB510L4-2 | 7/2 Vendor item drawing reference Northrop Grumman Systems Corporation |
| HT8043-4-2 | C/1 Advisory reference — outside the item-of-supply concept Howmet Global Fastening Systems Inc |
| A147-4-2 | C/1 Advisory reference — outside the item-of-supply concept Huck International, Inc |
| BM19025-4-2 | 5/9 Secondary reference U.S. Government activity |
| BM19025-4-2 | C/1 Advisory reference — outside the item-of-supply concept Huck International, Inc |
| GB510L4-2 | 5/2 Secondary reference U.S. Government activity |
| 106750-4-2 | 3/2 Design control — primary reference U.S. Government activity |
| A147-4-2 | 5/9 Secondary reference U.S. Government activity |
NSN 5305-01-044-8532 is a Screw,close Tolerance, manufactured by Hi-Shear Corporation, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-044-8532 has 2 manufacturer part numbers on file: HT239PB-4-2 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), HT239PB-4-2 (Hi-Shear Corporation).
1 possible match (shared part number, not a government interchangeability claim): 5935-01-114-7675. Verify interchangeability with system specifications before substitution.
Key specifications for HT239PB-4-2: Surface Finish: 63.0 MICROINCHES GRIP; Surface Finish: 63.0 MICROINCHES THREADS; Fastener Length: 0.425 INCHES MINIMUM AND 0.472 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-416,TYPE 2,CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL. 21 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.