The Nut,self-Locking,extended Washer, cataloged under National Stock Number 5310-01-116-1207, is classified within Federal Supply Class 5310 (Nuts and Washers) of the Hardware and Abrasives group. The manufacturer of record is The Boeing Company Div Defense. Government technical data includes 14 specifications, cited from the U.S. Government catalog. The record lists 6 manufacturer part numbers 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through both NSN and commercial part number lookups. 5 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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 | 5310-01-116-1207 |
| Primary Part Number | ST3M788-4 |
| Item Name | Nut,self-Locking,extended Washer |
| FSC / FSG | 5310 / 53 — Nuts and Washers |
| Manufacturer | The Boeing Company Div Defense |
| Status | ACTIVE |
| Lubrication | DRY FILM LUBRICANT |
| Washer Outside Diameter | 0.420 INCHES MAXIMUM IN |
| Width Across Flats | 0.306 INCHES MINIMUM AND 0.316 INCHES MAXIMUM IN |
| Thread Series | UNIFIED NATIONAL JOINT FINE (UNJF) |
| Temp Rating | 450.0 FAHRENHEIT NOMINAL DEGF |
| Washer Thickness | 0.020 INCHES NOMINAL IN |
| Material Document and Classification | AMS5737 NATIONAL SPEC ALL MATERIAL RESPONSES OR AMS5525 NATIONAL SPEC ALL MATERIAL RESPONSES OVERALL |
| Thread Direction | RIGHT-HAND |
| Nominal Thread Size | 0.250 INCHES IN |
| Locking Feature | PREVAILING TORQUE ALL METAL DESIGN |
| Nut Style | SLOTTED HEXAGON |
| Thread Class | 3B |
| Thread Quantity Per Inch | 28 |
| Material | IRON ALLOY 660 OVERALL |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | F |
| Part Number | Manufacturer |
|---|---|
| BH788-4 | Bristol Industries, Llc (USA) |
| MC15189 | Eaton Aerospace Llc Dba Sterer Engineering Div M.c.aerospace (USA) |
| ST3M788-4 | Paolo Astori Spa (ITA) |
| SLN206-3 | Space-Lok, Inc. Dba Space-Lok Inc Div Space-Lok (USA) |
| 79318CM-428 | Sps Technologies, Llc Dba PB Fasteners (USA) |
| ST3M788-4 PRIMARY | The Boeing Company Div Defense (USA) |
| Reference | Meaning |
|---|---|
| 10109286 | 6/9 Informative reference only Nimikkeistokeskus Ncb Finland |
| E12589-4 | 5/9 Secondary reference Harvard Industries Inc |
| E12589-4 | 5/9 Secondary reference Sps Technologies, Llc Dba PB Fasteners |
| E12589-4 | 5/2 Secondary reference U.S. Government activity |
| LCN12-428 | 5/9 Secondary reference Sps Technologies, Llc Dba PB Fasteners |
NSN 5310-01-116-1207 is a Nut,self-Locking,extended Washer, manufactured by The Boeing Company Div Defense, classified under FSC 5310, Nuts and Washers. Status: active.
NSN 5310-01-116-1207 has 6 manufacturer part numbers on file: BH788-4 (Bristol Industries, Llc), MC15189 (Eaton Aerospace Llc Dba Sterer Engineering Div M.c.aerospace), ST3M788-4 (Paolo Astori Spa), SLN206-3 (Space-Lok, Inc. Dba Space-Lok Inc Div Space-Lok), 79318CM-428 (Sps Technologies, Llc Dba PB Fasteners) and 1 more.
1 possible match (shared part number, not a government interchangeability claim): 5310-01-687-9456. Verify interchangeability with system specifications before substitution.
Key specifications for ST3M788-4: Lubrication: DRY FILM LUBRICANT; Overall Height: 0.173 INCHES MINIMUM AND 0.203 INCHES MAXIMUM IN; Washer Outside Diameter: 0.420 INCHES MAXIMUM IN; Width Across Flats: 0.306 INCHES MINIMUM AND 0.316 INCHES MAXIMUM IN. 14 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.