The Bolt,internally Relieved Body, cataloged under National Stock Number 5306-00-003-6569, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. The manufacturer of record is Northrop Grumman Systems Corporation. Government technical data includes 17 specifications, cited from the U.S. Government catalog. The record lists 1 manufacturer part number 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5306-00-003-6569 |
| Primary Part Number | A51B21643-21 |
| Item Name | Bolt,internally Relieved Body |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | Northrop Grumman Systems Corporation |
| Status | ACTIVE |
| Head Height | 0.190 INCHES NOMINAL IN |
| Surface Treatment Document and Classification | QQ-C-320 FED SPEC SINGLE TREATMENT RESPONSE GRIP |
| Thread Length | 0.890 INCHES NOMINAL IN |
| Style Designator | COUNTERBORE UNTHREADED |
| Material Document and Classification | G-1013 FSCM 26512 MFR REF SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.750 INCHES IN |
| Counterbore Depth | 0.490 INCHES NOMINAL IN |
| Head Style | FLAT CHAMFER |
| Thread Direction | RIGHT-HAND |
| Counterbore Diameter | 0.700 INCHES NOMINAL IN |
| Concentric Hole Diameter | 0.375 INCHES NOMINAL IN |
| Surface Treatment | CHROMIUM GRIP |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 16 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 1.500 INCHES NOMINAL 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 |
|---|---|
| A51B21643-21 PRIMARY | Northrop Grumman Systems Corporation (USA) |
| Reference | Meaning |
|---|---|
| A51B21643-21 | 3/9 Design control — primary reference Northrop Grumman Systems Corporation |
| A51B21643-21 | 5/9 Secondary reference Northrop Grumman Systems Corporation Dba Northrop Grumman Systems Corp Div Northrop Grumman Aeronautics Systems |
| A51B21643-21 | 5/9 Secondary reference S & L Aerospace Metals Llc |
NSN 5306-00-003-6569 is a Bolt,internally Relieved Body, manufactured by Northrop Grumman Systems Corporation, classified under FSC 5306, Bolts. Status: active.
NSN 5306-00-003-6569 has 1 manufacturer part number on file: A51B21643-21 (Northrop Grumman Systems Corporation).
Key specifications for A51B21643-21: Head Height: 0.190 INCHES NOMINAL IN; Surface Treatment Document and Classification: QQ-C-320 FED SPEC SINGLE TREATMENT RESPONSE GRIP; Thread Length: 0.890 INCHES NOMINAL IN; Style Designator: COUNTERBORE UNTHREADED. 17 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.