The Screw,close Tolerance, cataloged under National Stock Number 5305-01-250-0639, 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 17 specifications, cited from the U.S. Government catalog. The record lists 9 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 6 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-250-0639 |
| Primary Part Number | HT4049-3-21 |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Hi-Shear Corporation |
| Status | ACTIVE |
| Fastener Length | 1.573 INCHES MINIMUM AND 1.603 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.251 INCHES MINIMUM AND 0.301 INCHES MAXIMUM IN |
| Material Document and Classification | AMS 5629 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.190 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Grip Length | 1.302 INCHES MINIMUM AND 1.322 INCHES MAXIMUM IN |
| Grip Diameter | 0.1890 INCHES MINIMUM AND 0.1895 INCHES MAXIMUM IN |
| Surface Treatment | PASSIVATE OVERALL |
| Internal Drive Style | HIGH-TORQUE |
| Countersink Angle | 99.0 DEGREES MINIMUM AND 101.0 DEGREES MAXIMUM |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 32 |
| Material | STEEL COMP XM-13 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.376 INCHES MINIMUM AND 0.385 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 |
|---|---|
| HT4049-3-21 PRIMARY | Hi-Shear Corporation (USA) |
| ST3M714-3-21 PRIMARY | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| ST3M714-3-21 | The Boeing Company Div Defense (USA) |
| ST3M714-3-21 | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| HT4049-3-21 PRIMARY | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| HT4049-3-21 | Howmet Global Fastening Systems Inc (USA) |
| ST3M714-3-21 | Hi-Shear Corporation (USA) |
| WC4049-3-21 | West Coast Aerospace, Inc. (USA) |
| ST3M714-3-21 | West Coast Aerospace, Inc. (USA) |
| Reference | Meaning |
|---|---|
| ST3M714-3-21 | 5/9 Secondary reference U.S. Government activity |
| HT4049-3-21 | 5/2 Secondary reference U.S. Government activity |
| ST3M714-3-21 | 5/2 Secondary reference U.S. Government activity |
| HT4049-3-21 | 5/9 Secondary reference U.S. Government activity |
| HT4049-3-21 | 5/9 Secondary reference U.S. Government activity |
| HT4049-3-21 | C/1 Advisory reference — outside the item-of-supply concept Huck International, Inc |
NSN 5305-01-250-0639 is a Screw,close Tolerance, manufactured by Hi-Shear Corporation, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-250-0639 has 9 manufacturer part numbers on file: HT4049-3-21 (Hi-Shear Corporation), ST3M714-3-21 (Fastener Innovation Technology, Inc. Dba F I T), ST3M714-3-21 (The Boeing Company Div Defense), ST3M714-3-21 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), HT4049-3-21 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc) and 4 more.
Key specifications for HT4049-3-21: Fastener Length: 1.573 INCHES MINIMUM AND 1.603 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-35 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Thread Length: 0.251 INCHES MINIMUM AND 0.301 INCHES MAXIMUM IN; Material Document and Classification: AMS 5629 ASSN STD SINGLE MATERIAL RESPONSE OVERALL. 17 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.