The Screw,close Tolerance, cataloged under National Stock Number 5305-01-579-9838, 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 15 specifications, cited from the U.S. Government catalog. The record lists 18 manufacturer part numbers 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-01-579-9838 |
| Primary Part Number | HT4027-9-16 |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Hi-Shear Corporation |
| Status | ACTIVE |
| Fastener Length | 1.906 INCHES NOMINAL IN |
| Thread Length | 0.906 INCHES NOMINAL IN |
| Material Document and Classification | AMS5662 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.562 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Grip Length | 1.000 INCHES NOMINAL IN |
| Grip Diameter | 0.561 INCHES MINIMUM AND 0.562 INCHES MAXIMUM IN |
| Internal Drive Style | HIGH-TORQUE |
| Countersink Angle | 100.0 DEGREES NOMINAL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 18 |
| Material | NICKEL ALLOY 718 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.838 INCHES NOMINAL 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 |
|---|---|
| HT4027-9-16 | Huck International, Inc (USA) |
| WC4027-9-16 | West Coast Aerospace, Inc. (USA) |
| ST3M557-9-16 | Houston Precision Fasteners I Lp (USA) |
| HT4027-9-16 | Sps Technologies, Llc Dba PB Fasteners (USA) |
| ST3M557-9-16 | West Coast Aerospace, Inc. (USA) |
| ST3M557-9-16 | Linread Ltd (GBR) |
| ST3M557-9-16 | Huck International, Inc (USA) |
| 11923-9-16 | Reid Products Inc. Dba Reid Products Inc (USA) |
| ST3M557-9-16 | Camcar Llc Div Camcar Llc (USA) |
| HT4027-9-16 | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| ST3M557-9-16 | Saturn Fasteners Inc (USA) |
| ST3M557-9-16 | Reid Products Inc. Dba Reid Products Inc (USA) |
| ST3M557-9-16 | Heartland Precision Fasteners Inc (USA) |
| ST3M557-9-16 | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| HT4027-9-16 | Howmet Global Fastening Systems Inc (USA) |
| HT4027-9-16 PRIMARY | Hi-Shear Corporation (USA) |
| ST3M557-9-16 | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| ST3M557-9-16 | Valley-Todeco, Inc. Dba Arconic Fastening Systems (USA) |
| Reference | Meaning |
|---|---|
| ST3M557-9-16 | 7/2 Vendor item drawing reference The Boeing Company Div Defense |
| HT4027-9-16 | 5/2 Secondary reference U.S. Government activity |
| ST3M557-9-16 | 5/2 Secondary reference U.S. Government activity |
NSN 5305-01-579-9838 is a Screw,close Tolerance, manufactured by Hi-Shear Corporation, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-579-9838 has 18 manufacturer part numbers on file: HT4027-9-16 (Huck International, Inc), WC4027-9-16 (West Coast Aerospace, Inc.), ST3M557-9-16 (Houston Precision Fasteners I Lp), HT4027-9-16 (Sps Technologies, Llc Dba PB Fasteners), ST3M557-9-16 (West Coast Aerospace, Inc.) and 13 more.
Key specifications for HT4027-9-16: Fastener Length: 1.906 INCHES NOMINAL IN; Thread Length: 0.906 INCHES NOMINAL IN; Material Document and Classification: AMS5662 ASSN STD SINGLE MATERIAL RESPONSE OVERALL; Nominal Thread Diameter: 0.562 INCHES IN. 15 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.