The Screw,close Tolerance, cataloged under National Stock Number 5305-01-591-2219, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is West Coast Aerospace, Inc.. Government technical data includes 21 specifications, cited from the U.S. Government catalog. The record lists 15 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-01-591-2219 |
| Primary Part Number | WC4027-6-25 |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | West Coast Aerospace, Inc. |
| Status | ACTIVE |
| Head Height | 0.018 INCHES MAXIMUM IN |
| Point Length | 0.052 INCHES NOMINAL IN |
| Fastener Length | 2.189 INCHES MINIMUM AND 2.219 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | AMS 2700 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.641 INCHES NOMINAL IN |
| Material Document and Classification | AMS 5662 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Point Chamfer Angle | 45.0 DEGREES NOMINAL |
| Nominal Thread Diameter | 0.375 INCHES IN |
| Head Style | FILLISTER COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Point Style | FLAT |
| Grip Length | 1.553 INCHES MINIMUM AND 1.573 INCHES MAXIMUM IN |
| Grip Diameter | 0.374 INCHES MINIMUM AND 0.375 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 | 24 |
| Material | NICKEL ALLOY 718 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.510 INCHES MINIMUM AND 0.564 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 |
|---|---|
| ST3M557-6-25 | Heartland Precision Fasteners Inc (USA) |
| ST3M557-6-25 | Linread Ltd (GBR) |
| ST3M557-6-25 | Camcar Llc Div Camcar Llc (USA) |
| HT4027-6-25 | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| ST3M557-6-25 | Valley-Todeco, Inc. Dba Arconic Fastening Systems (USA) |
| ST3M557-6-25 | Saturn Fasteners Inc (USA) |
| WC4027-6-25 PRIMARY | West Coast Aerospace, Inc. (USA) |
| HT4027-6-25 | Sps Technologies, Llc Dba PB Fasteners (USA) |
| ST3M557-6-25 | Houston Precision Fasteners I Lp (USA) |
| HT4027-6-25 PRIMARY | Huck International, Inc (USA) |
| HT4027-6-25 | Hi-Shear Corporation (USA) |
| 11923-6-25 | Reid Products Inc. Dba Reid Products Inc (USA) |
| HT4027-6-25 | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| HT4027-6-25 | Howmet Global Fastening Systems Inc (USA) |
| HT4027-6-25 PRIMARY | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| Reference | Meaning |
|---|---|
| HT4027-6-25 | 5/2 Secondary reference U.S. Government activity |
| ST3M557-6-25 | 7/2 Vendor item drawing reference The Boeing Company Div Defense |
| HT4027-6-25 | 5/2 Secondary reference U.S. Government activity |
NSN 5305-01-591-2219 is a Screw,close Tolerance, manufactured by West Coast Aerospace, Inc., classified under FSC 5305, Screws. Status: active.
NSN 5305-01-591-2219 has 15 manufacturer part numbers on file: ST3M557-6-25 (Heartland Precision Fasteners Inc), ST3M557-6-25 (Linread Ltd), ST3M557-6-25 (Camcar Llc Div Camcar Llc), HT4027-6-25 (Sps Technologies Llc Dba PB Fasteners Div PB Fasteners), ST3M557-6-25 (Valley-Todeco, Inc. Dba Arconic Fastening Systems) and 10 more.
Key specifications for WC4027-6-25: Head Height: 0.018 INCHES MAXIMUM IN; Point Length: 0.052 INCHES NOMINAL IN; Fastener Length: 2.189 INCHES MINIMUM AND 2.219 INCHES MAXIMUM IN; Surface Treatment Document and Classification: AMS 2700 ASSN STD 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.