The Bolt,close Tolerance, cataloged under National Stock Number 5306-01-522-1729, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. The manufacturer of record is Sps Technologies Llc Dba PB Fasteners Div PB Fasteners. Government technical data includes 18 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-01-522-1729 |
| Primary Part Number | PBF7521-4-6R |
| Item Name | Bolt,close Tolerance |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners |
| Status | ACTIVE |
| Head Height | 0.164 INCHES NOMINAL IN |
| Fastener Length | 0.704 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | NAS672 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| Thread Length | 0.370 INCHES NOMINAL IN |
| Hardness Rating | 46.0 ROCKWELL C MINIMUM AND 50.0 ROCKWELL C MAXIMUM OVERALL |
| Material Document and Classification | AMS6487 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Head Style | SPLINE DRIVE SHEAR HEAD |
| Thread Direction | RIGHT-HAND |
| Grip Length | 0.250 INCHES NOMINAL IN |
| Head Minor Diameter | 0.359 INCHES MINIMUM AND 0.380 INCHES MAXIMUM IN |
| Grip Diameter | 0.2483 INCHES MINIMUM AND 0.2492 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM OVERALL |
| Minimum Tensile Strength | 6980 POUNDS PER SQUARE INCH LBS |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | STEEL COMP H11 OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| 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 |
|---|---|
| PBF7521-4-6R PRIMARY | Sps Technologies Llc Dba PB Fasteners Div PB Fasteners (USA) |
| VCG0009-4-6R PRIMARY | Valley-Todeco, Inc. Dba Arconic Fastening Systems (USA) |
| AIC596-4-6R PRIMARY | Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company (USA) |
| H411-4-6R PRIMARY | Huck International, Inc (USA) |
| 120978-4-6R PRIMARY | Sps Technologies, Llc Dba PB Fasteners (USA) |
| Reference | Meaning |
|---|---|
| 120978-4-6R | 3/2 Design control — primary reference U.S. Government activity |
| VS3133-4-6R | 3/2 Design control — primary reference U.S. Government activity |
| C7521-4-6R | 7/2 Vendor item drawing reference U.S. Government activity |
NSN 5306-01-522-1729 is a Bolt,close Tolerance, manufactured by Sps Technologies Llc Dba PB Fasteners Div PB Fasteners, classified under FSC 5306, Bolts. Status: active.
NSN 5306-01-522-1729 has 5 manufacturer part numbers on file: PBF7521-4-6R (Sps Technologies Llc Dba PB Fasteners Div PB Fasteners), VCG0009-4-6R (Valley-Todeco, Inc. Dba Arconic Fastening Systems), AIC596-4-6R (Sps Technologies, Llc Dba Air Industries Company Div Air Industries Company), H411-4-6R (Huck International, Inc), 120978-4-6R (Sps Technologies, Llc Dba PB Fasteners).
Key specifications for PBF7521-4-6R: Head Height: 0.164 INCHES NOMINAL IN; Fastener Length: 0.704 INCHES NOMINAL IN; Surface Treatment Document and Classification: NAS672 ASSN STD SINGLE TREATMENT RESPONSE OVERALL; Thread Length: 0.370 INCHES NOMINAL 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.