The Screw,close Tolerance, cataloged under National Stock Number 5305-01-563-3843, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is The Boeing Company Div Defense. Government technical data includes 15 specifications, cited from the U.S. Government catalog. The record lists 16 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-563-3843 |
| Primary Part Number | ST3M557-6-5 |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Fastener Length | 0.951 INCHES NOMINAL IN |
| Thread Length | 0.641 INCHES NOMINAL IN |
| Nominal Thread Diameter | 0.375 INCHES IN |
| Head Style | OVAL COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Grip Length | 0.615 INCHES MINIMUM AND 0.635 INCHES MAXIMUM IN |
| Grip Diameter | 0.374 INCHES NOMINAL 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 | 24 |
| Material | NICKEL ALLOY 718 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.564 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 |
|---|---|
| HT4027-6-5 | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| HT4027-6-5 | Huck International, Inc (USA) |
| ST3M557-6-5 | Camcar Llc Div Camcar Llc (USA) |
| ST3M557-6-5 | Saturn Fasteners Inc (USA) |
| HT4027-6-5 | Sps Technologies, Llc Dba PB Fasteners (USA) |
| HT4027-6-5 | Hi-Shear Corporation (USA) |
| ST3M557-6-5 | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| 11923-6-5 | Reid Products Inc. Dba Reid Products Inc (USA) |
| ST3M557-6-5 | Heartland Precision Fasteners Inc (USA) |
| HT4027-6-5 | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| HT4027-6-5 | Howmet Global Fastening Systems Inc (USA) |
| WC4027-6-5 | West Coast Aerospace, Inc. (USA) |
| ST3M557-6-5 | Valley-Todeco, Inc. Dba Arconic Fastening Systems (USA) |
| ST3M557-6-5 | Houston Precision Fasteners I Lp (USA) |
| HT4027-6-5 | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| ST3M557-6-5 PRIMARY | The Boeing Company Div Defense (USA) |
| Reference | Meaning |
|---|---|
| HT4027-6-5 | 5/2 Secondary reference U.S. Government activity |
| HT4027-6-5 | 5/2 Secondary reference U.S. Government activity |
NSN 5305-01-563-3843 is a Screw,close Tolerance, manufactured by The Boeing Company Div Defense, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-563-3843 has 16 manufacturer part numbers on file: HT4027-6-5 (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), HT4027-6-5 (Huck International, Inc), ST3M557-6-5 (Camcar Llc Div Camcar Llc), ST3M557-6-5 (Saturn Fasteners Inc), HT4027-6-5 (Sps Technologies, Llc Dba PB Fasteners) and 11 more.
Key specifications for ST3M557-6-5: Fastener Length: 0.951 INCHES NOMINAL IN; Thread Length: 0.641 INCHES NOMINAL IN; Nominal Thread Diameter: 0.375 INCHES IN; Head Style: OVAL COUNTERSUNK. 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.