The Screw,close Tolerance, cataloged under National Stock Number 5305-01-374-5945, 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 18 specifications, cited from the U.S. Government catalog. The record lists 7 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through both NSN and commercial part number lookups. 8 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-01-374-5945 |
| Primary Part Number | HT271A4-8M |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Hi-Shear Corporation |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES THREADS |
| Surface Finish | 32.0 MICROINCHES BEARING SURFACE OF HEAD |
| Head Height | 0.1060 INCHES MINIMUM AND 0.1080 INCHES MAXIMUM IN |
| Fastener Length | 0.963 INCHES MINIMUM AND 0.990 INCHES MAXIMUM IN |
| Thread Length | 0.469 INCHES NOMINAL IN |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Features Provided | DRY FILM LUBRICANT AND O RING |
| Head Style | FLAT COUNTERSUNK UNDERCUT |
| Thread Direction | RIGHT-HAND |
| Grip Length | 0.490 INCHES MINIMUM AND 0.510 INCHES MAXIMUM IN |
| Grip Diameter | 0.2490 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN |
| Internal Drive Style | HIGH-TORQUE |
| Countersink Angle | 100.0 DEGREES NOMINAL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | TITANIUM ALLOY UNS R56400 OR TITANIUM ALLOY UNS R56440 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.5018 INCHES MINIMUM AND 0.5066 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 |
|---|---|
| 110179-4-8ASM | Sps Technologies Ltd, Tj Brooks Division (GBR) |
| HT271A4-8M PRIMARY | Hi-Shear Corporation (USA) |
| HT8137-4-8ASM PRIMARY | Howmet Global Fastening Systems Inc. Div Voi-Shan Products (USA) |
| HT271A4-8M PRIMARY | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| ST3M430V4-8ASM | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| ST3M430V4-8ASM | Huck International, Inc (USA) |
| BM33024V4-8UM PRIMARY | Huck International, Inc (USA) |
| Reference | Meaning |
|---|---|
| ST3M40V4-8ASM | 5/9 Secondary reference Huck International, Inc |
| ST3M40V4-8ASM | 5/9 Secondary reference U.S. Government activity |
| ST3M40V4-8ASM | 5/9 Secondary reference Sps Technologies Ltd, Tj Brooks Division |
| ST3M40V4-8ASM | 5/9 Secondary reference U.S. Government activity |
| HT8137-4-8ASM | 5/9 Secondary reference U.S. Government activity |
| ST3M40V4-8ASM | 5/9 Secondary reference Hi-Shear Corporation |
| ST3M430V4-8ASM | 7/2 Vendor item drawing reference The Boeing Company Div Defense |
| 110179-4-8ASM | 3/2 Design control — primary reference U.S. Government activity |
NSN 5305-01-374-5945 is a Screw,close Tolerance, manufactured by Hi-Shear Corporation, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-374-5945 has 7 manufacturer part numbers on file: 110179-4-8ASM (Sps Technologies Ltd, Tj Brooks Division), HT271A4-8M (Hi-Shear Corporation), HT8137-4-8ASM (Howmet Global Fastening Systems Inc. Div Voi-Shan Products), HT271A4-8M (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), ST3M430V4-8ASM (Fastener Innovation Technology, Inc. Dba F I T) and 2 more.
Key specifications for HT271A4-8M: Surface Finish: 32.0 MICROINCHES THREADS; Surface Finish: 32.0 MICROINCHES BEARING SURFACE OF HEAD; Head Height: 0.1060 INCHES MINIMUM AND 0.1080 INCHES MAXIMUM IN; Fastener Length: 0.963 INCHES MINIMUM AND 0.990 INCHES MAXIMUM IN. 18 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.