The Bolt,internally Relieved Body, cataloged under National Stock Number 5306-01-386-8147, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. The manufacturer of record is Northrop Grumman Systems Corporation Dba Northrop Grumman Systems Corp. Government technical data includes 20 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-01-386-8147 |
| Primary Part Number | A51B24668-21 |
| Item Name | Bolt,internally Relieved Body |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | Northrop Grumman Systems Corporation Dba Northrop Grumman Systems Corp |
| Status | ACTIVE |
| Head Height | 0.145 INCHES NOMINAL IN |
| Fastener Length | 3.928 INCHES MINIMUM AND 3.933 INCHES MAXIMUM IN |
| Surface Treatment Document and Classification | GSS9056, CAGE 26512 MFR REF SINGLE TREATMENT RESPONSE OVERALL |
| Distance From Centerline to Flat | 0.569 INCHES NOMINAL IN |
| Concentric Hole Depth | 2.878 INCHES MINIMUM AND 2.883 INCHES MAXIMUM IN |
| Thread Length | 0.297 INCHES NOMINAL IN |
| Hardness Rating | 46.0 ROCKWELL C MINIMUM AND 49.0 ROCKWELL C MAXIMUM OVERALL |
| Style Designator | CONCENTRIC HOLE UNTHREADED |
| Material Document and Classification | G-1010, CAGE 26512 MFR REF SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.375 INCHES IN |
| Head Style | DEE CHAMFER |
| Thread Direction | RIGHT-HAND |
| Shoulder Diameter | 1.1468 INCHES MINIMUM AND 1.1473 INCHES MAXIMUM IN |
| Concentric Hole Diameter | 0.499 INCHES MINIMUM AND 0.506 INCHES MAXIMUM IN |
| Surface Treatment | CADMIUM OVERALL |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 24 |
| Shoulder Length | 3.318 INCHES MINIMUM AND 3.323 INCHES MAXIMUM IN |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Head Diameter | 1.710 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 |
|---|---|
| A51B24668-21 PRIMARY | Northrop Grumman Systems Corporation Dba Northrop Grumman Systems Corp (USA) |
| Reference | Meaning |
|---|---|
| A51B24668-21 | 5/9 Secondary reference Northrop Grumman Systems Corporation Dba Northrop Grumman Systems Corp Div Northrop Grumman Aeronautics Systems |
| A51B24668-21 | 5/9 Secondary reference Northrop Grumman Systems Corporation |
NSN 5306-01-386-8147 is a Bolt,internally Relieved Body, manufactured by Northrop Grumman Systems Corporation Dba Northrop Grumman Systems Corp, classified under FSC 5306, Bolts. Status: active.
NSN 5306-01-386-8147 has 1 manufacturer part number on file: A51B24668-21 (Northrop Grumman Systems Corporation Dba Northrop Grumman Systems Corp).
Key specifications for A51B24668-21: Head Height: 0.145 INCHES NOMINAL IN; Fastener Length: 3.928 INCHES MINIMUM AND 3.933 INCHES MAXIMUM IN; Surface Treatment Document and Classification: GSS9056, CAGE 26512 MFR REF SINGLE TREATMENT RESPONSE OVERALL; Distance From Centerline to Flat: 0.569 INCHES NOMINAL 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.