The Bolt,machine, cataloged under National Stock Number 5306-01-274-8315, is classified within Federal Supply Class 5306 (Bolts) of the Hardware and Abrasives group. The manufacturer of record is Leonardo Spa Helicopters Division - Production Site. Government technical data includes 19 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5306-01-274-8315 |
| Primary Part Number | MS9557-12 |
| Item Name | Bolt,machine |
| FSC / FSG | 5306 / 53 — Bolts |
| Manufacturer | Leonardo Spa Helicopters Division - Production Site |
| Status | ACTIVE |
| Surface Finish | 32.0 MICROINCHES THREADS |
| Surface Finish | 32.0 MICROINCHES GRIP |
| Surface Finish | 32.0 MICROINCHES BEARING SURFACE OF HEAD |
| Extended Washer Thickness | 0.060 INCHES NOMINAL IN |
| Head Height | 0.300 INCHES NOMINAL IN |
| Fastener Length | 0.865 INCHES MINIMUM AND 0.885 INCHES MAXIMUM IN |
| Extended Washer Diameter | 0.438 INCHES NOMINAL IN |
| Thread Length | 0.740 INCHES MINIMUM AND 0.806 INCHES MAXIMUM IN |
| Material Document and Classification | AMS 5731 ASSN STD SINGLE MATERIAL RESPONSE OVERALL |
| Nominal Thread Diameter | 0.250 INCHES IN |
| Features Provided | FINISHED HEAD |
| Head Style | DOUBLE HEXAGON EXTENDED WASHER |
| Thread Direction | RIGHT-HAND |
| Grip Length | 0.079 INCHES MINIMUM AND 0.125 INCHES MAXIMUM IN |
| Width Between Flats | 0.312 INCHES NOMINAL IN |
| Thread Class | 3A A |
| Thread Quantity Per Inch | 28 |
| Material | IRON ALLOY 660 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 |
|---|---|
| MS9557-12 | Leonardo Spa Helicopters Division - Production Site (ITA) |
| Reference | Meaning |
|---|---|
| MS9557-12 | 5/2 Secondary reference U.S. Government activity |
| 5306PL0626049 | 6/9 Informative reference only Jednolity Indeks Materialowy - Uniform Material Index |
| MS9557-12 | 4/1 Identification reference U.S. Government activity |
| MS9557-12 | 3/2 Design control — primary reference U.S. Government activity |
| J644P11E | C/1 Advisory reference — outside the item-of-supply concept Zf Industrieantriebe Witten Gmbh |
NSN 5306-01-274-8315 is a Bolt,machine, manufactured by Leonardo Spa Helicopters Division - Production Site, classified under FSC 5306, Bolts. Status: active.
NSN 5306-01-274-8315 has 1 manufacturer part number on file: MS9557-12 (Leonardo Spa Helicopters Division - Production Site).
1 possible match (shared part number, not a government interchangeability claim): 5306-01-481-6662. Verify interchangeability with system specifications before substitution.
Key specifications for MS9557-12: Surface Finish: 32.0 MICROINCHES THREADS; Surface Finish: 32.0 MICROINCHES GRIP; Surface Finish: 32.0 MICROINCHES BEARING SURFACE OF HEAD; Extended Washer Thickness: 0.060 INCHES NOMINAL IN. 19 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.