The Screw,shoulder, cataloged under National Stock Number 5305-01-184-3777, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Sonic Industries, Inc. Dba Sonic Industries Inc Div Sonic Industries. 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through both NSN and commercial part number lookups. 6 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-01-184-3777 |
| Primary Part Number | BACB30LU8-21Y |
| Item Name | Screw,shoulder |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Sonic Industries, Inc. Dba Sonic Industries Inc Div Sonic Industries |
| Status | ACTIVE |
| Fastener Length | 1.385 INCHES MINIMUM AND 1.405 INCHES MAXIMUM IN |
| Shoulder Length | 0.645 INCHES MINIMUM AND 0.665 INCHES MAXIMUM FIRST SHOULDER IN |
| Surface Treatment Document and Classification | QQ-P-416 TYPE 2 CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Shoulder Diameter | 0.5297 INCHES MINIMUM AND 0.5307 INCHES MAXIMUM FIRST SHOULDER IN |
| Thread Length | 0.735 INCHES NOMINAL IN |
| Shoulder Shape | ROUND FIRST SHOULDER |
| Material Document and Classification | MIL-S-5000 MIL SPEC 1ST MATERIAL RESPONSE OR MIL-S-6049 MIL SPEC 2ND MATERIAL RESPONSE OR AMS 6322 ASSN STD 2ND MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.500 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Internal Drive Style | CROSS RECESS TYPE 1 |
| Countersink Angle | 99.0 DEGREES MINIMUM AND 101.0 DEGREES MAXIMUM |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 20 |
| Material | STEEL COMP E4340 OR STEEL COMP 8740 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.927 INCHES MINIMUM AND 1.019 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 |
|---|---|
| BACB30LU8-21Y | Sonic Industries, Inc. Dba Sonic Industries Inc Div Sonic Industries (USA) |
| BACB30LU8-21Y | Howmet Global Fastening Systems Inc (USA) |
| BACB30LU8-21Y | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| BACB30LU8-21Y | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| BACB30LU8-21Y | Federal Manufacturing Corp (USA) |
| BACB30LU8-21Y | Valley-Todeco, Inc. Dba Arconic Fastening Systems (USA) |
| Reference | Meaning |
|---|---|
| BACB30LU8-21Y | 5/2 Secondary reference U.S. Government activity |
| BACB30LU8-21Y | 3/2 Design control — primary reference U.S. Government activity |
| BACB30LU8-21Y | 5/2 Secondary reference U.S. Government activity |
| BACB30LU8-21Y | 5/9 Secondary reference U.S. Government activity |
| BACB30LU8-21Y | 5/9 Secondary reference Sps Technologies, Llc Dba PB Fasteners |
| BACB30LU8-21Y | C/1 Advisory reference — outside the item-of-supply concept Huck International, Inc |
NSN 5305-01-184-3777 is a Screw,shoulder, manufactured by Sonic Industries, Inc. Dba Sonic Industries Inc Div Sonic Industries, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-184-3777 has 6 manufacturer part numbers on file: BACB30LU8-21Y (Sonic Industries, Inc. Dba Sonic Industries Inc Div Sonic Industries), BACB30LU8-21Y (Howmet Global Fastening Systems Inc), BACB30LU8-21Y (Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company), BACB30LU8-21Y (Sps Technologies Llc Dba PB Fasteners Div PB Fasteners), BACB30LU8-21Y (Federal Manufacturing Corp) and 1 more.
Key specifications for BACB30LU8-21Y: Fastener Length: 1.385 INCHES MINIMUM AND 1.405 INCHES MAXIMUM IN; Shoulder Length: 0.645 INCHES MINIMUM AND 0.665 INCHES MAXIMUM FIRST SHOULDER IN; Surface Treatment Document and Classification: QQ-P-416 TYPE 2 CLASS 2 FED SPEC SINGLE TREATMENT RESPONSE OVERALL; Shoulder Diameter: 0.5297 INCHES MINIMUM AND 0.5307 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.