The Bolt,shoulder, cataloged under National Stock Number 5306-00-972-3963, 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 23 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through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog.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 | 5306-00-972-3963 |
| Primary Part Number | A51B27581-13 |
| Item Name | Bolt,shoulder |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | Northrop Grumman Systems Corporation |
| Status | ACTIVE |
| Head Height | 0.250 INCHES NOMINAL IN |
| Fastener Length | 3.096 INCHES NOMINAL IN |
| Shoulder Length | 2.456 INCHES NOMINAL FIRST SHOULDER IN |
| Surface Treatment Document and Classification | AMS 2410 ASSN STD SINGLE TREATMENT RESPONSE OVERALL |
| Precious Material | SILVER |
| Shoulder Diameter | 1.2465 INCHES MINIMUM AND 1.2470 INCHES MAXIMUM FIRST SHOULDER IN |
| Thread Length | 0.640 INCHES MAXIMUM IN |
| Shoulder Shape | ROUND FIRST SHOULDER |
| Hardness Rating | 46.0 ROCKWELL C MINIMUM AND 49.0 ROCKWELL C MAXIMUM OVERALL |
| Shank Unthreaded Hole Diameter | 0.141 INCHES NOMINAL FIRST HOLE IN |
| Material Document and Classification | MIL-S-8949 MIL SPEC SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.875 INCHES IN |
| Head Style | ROUND W/WRENCH FLATS |
| Thread Direction | RIGHT-HAND |
| Width Between Flats | 1.500 INCHES NOMINAL IN |
| Surface Treatment | SILVER OVERALL |
| Thread Class | 3A A |
| Test Data Document | 81349-MIL-I-6868 SPECIFICATION (INCLUDES ENGINEERING TYPE BULLETINS, BROCHURES,ETC., THAT REFLECT SPECIFICATION TYPE DATA IN SPECIFICATION FORMAT; EXCLUDES COMMERCIAL CATALOGS, INDUSTRY DIRECTORIES, AND SIMILAR TRADE PUBLICATIONS, REFLECTING GENERAL TYPE DATA ON CERTAIN ENVIRONMENTAL AND PERFORMANCE REQUIREMENTS AND TEST CONDITIONS THAT ARE SHOWN AS "TYPICAL", "AVERAGE", "NOMINAL", ETC.). |
| Thread Quantity Per Inch | 14 |
| Material | STEEL OVERALL |
| Thread Series Designator | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Distance From Head Largest Bearing Surface to Shank Hole Center | 2.956 INCHES NOMINAL FIRST HOLE IN |
| Head Diameter | 1.750 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 |
|---|---|
| A51B27581-13 PRIMARY | Northrop Grumman Systems Corporation (USA) |
| Reference | Meaning |
|---|---|
| A51B27581-13 | 3/9 Design control — primary reference Northrop Grumman Systems Corporation Dba Northrop Grumman Systems Corp Div Northrop Grumman Aeronautics Systems |
| A51B27581-13 | 5/9 Secondary reference Northrop Grumman Systems Corporation |
NSN 5306-00-972-3963 is a Bolt,shoulder, manufactured by Northrop Grumman Systems Corporation, classified under FSC 5306, Bolts. Status: active.
NSN 5306-00-972-3963 has 1 manufacturer part number on file: A51B27581-13 (Northrop Grumman Systems Corporation).
Key specifications for A51B27581-13: Head Height: 0.250 INCHES NOMINAL IN; Fastener Length: 3.096 INCHES NOMINAL IN; Shoulder Length: 2.456 INCHES NOMINAL FIRST SHOULDER IN; Surface Treatment Document and Classification: AMS 2410 ASSN STD SINGLE TREATMENT RESPONSE OVERALL. 23 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.