The Ring,retaining, cataloged under National Stock Number 5325-00-447-8837, is classified within Federal Supply Class 5325 (Fastening Devices) of the Hardware and Abrasives group. The manufacturer of record is Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic. Government technical data includes 9 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through both NSN and commercial part number lookups. 3 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 5 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5325-00-447-8837 |
| Primary Part Number | A1780 |
| Item Name | Ring,retaining |
| FSC / FSG | 5325 / 53 — Fastening Devices |
| Manufacturer | Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic |
| Status | ACTIVE |
| Usage Design | EXTERNAL |
| End Style | VERTEX CENTER OR ABOVE |
| Cross-Sectional Shape Style | RECTANGULAR |
| Outside Diameter | 5.188 INCHES NOMINAL IN |
| Major Thickness | 0.125 INCHES NOMINAL IN |
| Inside Diameter | 4.938 INCHES NOMINAL IN |
| Casehardening Indicator | NOT CASEHARDENED |
| Ring Style | STRAIGHT GAP |
| Material | STEEL |
| 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 |
|---|---|
| A1780 PRIMARY | Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic (USA) |
| Reference | Meaning |
|---|---|
| SU3016 | 5/9 Secondary reference Koehring Cranes and Excavators Inc Sub of Northwest Engineering Co |
| N2730A | 5/9 Secondary reference Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic |
| SU3016 | 5/9 Secondary reference Koehring Co Lorain Div |
NSN 5325-00-447-8837 is a Ring,retaining, manufactured by Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic, classified under FSC 5325, Fastening Devices. Status: active.
NSN 5325-00-447-8837 has 1 manufacturer part number on file: A1780 (Twin Disc, Incorporated Dba Twin Disc Mid-Atlantic).
5 possible matches (shared part number, not a government interchangeability claim): 3120-01-067-3325, 8455-01-339-1870, 8455-01-528-8756. Verify interchangeability with system specifications before substitution.
Key specifications for A1780: Usage Design: EXTERNAL; End Style: VERTEX CENTER OR ABOVE; Cross-Sectional Shape Style: RECTANGULAR; Outside Diameter: 5.188 INCHES NOMINAL IN. 9 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.