The Screw,shoulder, cataloged under National Stock Number 5305-01-191-7496, 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 18 specifications, cited from the U.S. Government catalog. The record lists 6 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through both NSN and commercial part number lookups. 6 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-01-191-7496 |
| Primary Part Number | WC4020-4-5AX |
| Item Name | Screw,shoulder |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | West Coast Aerospace, Inc. |
| Status | ACTIVE |
| Head Height | 0.065 INCHES MINIMUM AND 0.067 INCHES MAXIMUM IN |
| Fastener Length | 0.765 INCHES MINIMUM AND 0.812 INCHES MAXIMUM IN |
| Shoulder Length | 0.237 INCHES MINIMUM AND 0.255 INCHES MAXIMUM FIRST SHOULDER IN |
| Shoulder Diameter | 0.2646 INCHES MINIMUM AND 0.2651 INCHES MAXIMUM FIRST SHOULDER IN |
| Thread Length | 0.410 INCHES MINIMUM AND 0.443 INCHES MAXIMUM IN |
| Shoulder Shape | ROUND FIRST SHOULDER |
| Material Document and Classification | ST7-251 FSCM 76301 MFR REF SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FLAT COUNTERSUNK UNDERCUT |
| Thread Direction | RIGHT-HAND |
| Minimum Tensile Strength | 125000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HIGH-TORQUE |
| Countersink Angle | 99.0 DEGREES MINIMUM AND 101.0 DEGREES MAXIMUM |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL CORROSION RESISTING OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.502 INCHES MINIMUM AND 0.507 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 |
|---|---|
| WC4020-4-5AX PRIMARY | West Coast Aerospace, Inc. (USA) |
| ST3M653C4-5A PRIMARY | Fastener Innovation Technology, Inc. Dba F I T (USA) |
| HT4020-4-5AX PRIMARY | Howmet Global Fastening Systems Inc (USA) |
| HT4020-4-5AX PRIMARY | Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc (CAN) |
| HT4020-4-5AX PRIMARY | Hi-Shear Corporation (USA) |
| ST3M653C4-5A | Sps Technologies, Llc Dba PB Fasteners (USA) |
| Reference | Meaning |
|---|---|
| ST3M653C4-5A | 5/2 Secondary reference U.S. Government activity |
| HT4020-4-5AX | C/1 Advisory reference — outside the item-of-supply concept Huck International, Inc |
| HT4020-4-5AX | 5/9 Secondary reference U.S. Government activity |
| HT4020-4-5AX | 3/2 Design control — primary reference U.S. Government activity |
| ST3M653C4-5A | 7/2 Vendor item drawing reference The Boeing Company Div Defense |
| HT4020-4-5AX | 5/9 Secondary reference U.S. Government activity |
NSN 5305-01-191-7496 is a Screw,shoulder, manufactured by West Coast Aerospace, Inc., classified under FSC 5305, Screws. Status: active.
NSN 5305-01-191-7496 has 6 manufacturer part numbers on file: WC4020-4-5AX (West Coast Aerospace, Inc.), ST3M653C4-5A (Fastener Innovation Technology, Inc. Dba F I T), HT4020-4-5AX (Howmet Global Fastening Systems Inc), HT4020-4-5AX (Lisi Aerospace Canada Corp Div Hi Shear Holdings Inc), HT4020-4-5AX (Hi-Shear Corporation) and 1 more.
Key specifications for WC4020-4-5AX: Head Height: 0.065 INCHES MINIMUM AND 0.067 INCHES MAXIMUM IN; Fastener Length: 0.765 INCHES MINIMUM AND 0.812 INCHES MAXIMUM IN; Shoulder Length: 0.237 INCHES MINIMUM AND 0.255 INCHES MAXIMUM FIRST SHOULDER IN; Shoulder Diameter: 0.2646 INCHES MINIMUM AND 0.2651 INCHES MAXIMUM FIRST SHOULDER 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.