The Screw,close Tolerance, cataloged under National Stock Number 5305-01-056-5451, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Valley-Todeco, Inc. Dba Arconic Fastening Systems. Government technical data includes 20 specifications, cited from the U.S. Government catalog. The record lists 5 manufacturer part numbers for this item, enabling identification through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5305-01-056-5451 |
| Primary Part Number | BACB30LK3-8 |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Valley-Todeco, Inc. Dba Arconic Fastening Systems |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES THREADS |
| Surface Finish | 32.0 MICROINCHES GRIP |
| Surface Finish | 32.0 MICROINCHES BEARING SURFACE OF HEAD |
| Head Height | 0.122 INCHES MINIMUM AND 0.133 INCHES MAXIMUM IN |
| Fastener Length | 0.830 INCHES MINIMUM AND 0.860 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416,TYPE 2,CLASS 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.320 INCHES MINIMUM AND 0.370 INCHES MAXIMUM IN |
| Nominal Thread Diameter | 0.190 INCHES IN |
| Head Style | PAN |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 81205-BACB30LK MANUFACTURERS STANDARD |
| Grip Length | 0.490 INCHES MINIMUM AND 0.510 INCHES MAXIMUM IN |
| Grip Diameter | 0.1885 INCHES MINIMUM AND 0.1895 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Internal Drive Style | CROSS RECESS TYPE 1 |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 32 |
| Material | IRON ALLOY 660 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 0.357 INCHES MINIMUM AND 0.373 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 |
|---|---|
| BACB30LK3-8 | Valley-Todeco, Inc. Dba Arconic Fastening Systems (USA) |
| BACB30LK3-8 | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| BACB30LK3-8 | Huck International, Inc (USA) |
| BACB30LK3-8 | Federal Manufacturing Corp (USA) |
| BACB30LK3-8 | Howmet Global Fastening Systems Inc (USA) |
| Reference | Meaning |
|---|---|
| BACB30LK3-8 | 5/9 Secondary reference U.S. Government activity |
| BACB30LK3-8 | 5/2 Secondary reference U.S. Government activity |
| BACB30LK3-8 | 5/9 Secondary reference Rca Corp Rca Records |
| BACB30LK3-8 | 3/2 Design control — primary reference U.S. Government activity |
| BACB30LK3-8 | 5/9 Secondary reference U.S. Government activity |
NSN 5305-01-056-5451 is a Screw,close Tolerance, manufactured by Valley-Todeco, Inc. Dba Arconic Fastening Systems, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-056-5451 has 5 manufacturer part numbers on file: BACB30LK3-8 (Valley-Todeco, Inc. Dba Arconic Fastening Systems), BACB30LK3-8 (Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company), BACB30LK3-8 (Huck International, Inc), BACB30LK3-8 (Federal Manufacturing Corp), BACB30LK3-8 (Howmet Global Fastening Systems Inc).
1 possible match (shared part number, not a government interchangeability claim): 5305-01-669-4478. Verify interchangeability with system specifications before substitution.
Key specifications for BACB30LK3-8: Surface Finish: 32.0 MICROINCHES THREADS; Surface Finish: 32.0 MICROINCHES GRIP; Surface Finish: 32.0 MICROINCHES BEARING SURFACE OF HEAD; Head Height: 0.122 INCHES MINIMUM AND 0.133 INCHES MAXIMUM IN. 20 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.