The Screw,close Tolerance, cataloged under National Stock Number 5305-01-057-0359, is classified within Federal Supply Class 5305 (Screws) of the Hardware and Abrasives group. The manufacturer of record is Sps Technologies, Llc Dba PB Fasteners. Government technical data includes 21 specifications, cited from the U.S. Government catalog. The record lists 2 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5305-01-057-0359 |
| Primary Part Number | BACB30EL4-16 |
| Item Name | Screw,close Tolerance |
| FSC / FSG | 5305 / 53 — Screws |
| Manufacturer | Sps Technologies, Llc Dba PB Fasteners |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES THREADS |
| Surface Finish | 63.0 MICROINCHES GRIP |
| Fastener Length | 1.301 INCHES MINIMUM AND 1.331 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | QQ-P-416,TYPE 2,CLASS 3 FED SPEC SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.291 INCHES MINIMUM AND 0.341 INCHES MAXIMUM IN |
| Hardness Rating | 36.0 ROCKWELL C MINIMUM AND 40.0 ROCKWELL C MAXIMUM OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | FLAT COUNTERSUNK |
| Thread Direction | RIGHT-HAND |
| Specification/standard Data | 81205-BACB30EL MANUFACTURERS STANDARD |
| Grip Length | 0.990 INCHES MINIMUM AND 1.010 INCHES MAXIMUM IN |
| Grip Diameter | 0.2485 INCHES MINIMUM AND 0.2495 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM AND CHROMATE OVERALL |
| Minimum Tensile Strength | 160000 POUNDS PER SQUARE INCH LBS |
| Internal Drive Style | HIGH-TORQUE |
| Countersink Angle | 100.0 DEGREES NOMINAL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL COMP 4140 OR STEEL COMP E4340 OR STEEL COMP 6150 OR STEEL COMP 8735 OR STEEL COMP 8740 OR STEEL COMP 4130 OVERALL |
| Thread Series Designator | UNF |
| Head Diameter | 0.350 INCHES MINIMUM AND 0.399 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 |
|---|---|
| BACB30EL4-16 | Sps Technologies, Llc Dba PB Fasteners (USA) |
| BACB30EL4-16 | Hi-Shear Corporation (USA) |
| Reference | Meaning |
|---|---|
| BACB30EL4-16 | 3/2 Design control — primary reference U.S. Government activity |
| BACB30EL4-16 | 5/2 Secondary reference U.S. Government activity |
NSN 5305-01-057-0359 is a Screw,close Tolerance, manufactured by Sps Technologies, Llc Dba PB Fasteners, classified under FSC 5305, Screws. Status: active.
NSN 5305-01-057-0359 has 2 manufacturer part numbers on file: BACB30EL4-16 (Sps Technologies, Llc Dba PB Fasteners), BACB30EL4-16 (Hi-Shear Corporation).
Key specifications for BACB30EL4-16: Surface Finish: 32.0 MICROINCHES THREADS; Surface Finish: 63.0 MICROINCHES GRIP; Fastener Length: 1.301 INCHES MINIMUM AND 1.331 INCHES MAXIMUM IN; Surface Treatment Document and Classification: QQ-P-416,TYPE 2,CLASS 3 FED SPEC 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.