The Ring,retaining, cataloged under National Stock Number 5325-01-340-4901, is classified within Federal Supply Class 5325 (Fastening Devices) of the Hardware and Abrasives group. The manufacturer of record is Bsi Standards Limited. 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. Current acquisition status: Active.
| Parameter | Value |
|---|---|
| NSN | 5325-01-340-4901 |
| Primary Part Number | AS4570-81 |
| Item Name | Ring,retaining |
| FSC / FSG | 5325 / 53 — Fastening Devices |
| Manufacturer | Bsi Standards Limited |
| Status | ACTIVE |
| Usage Design | EXTERNAL |
| End Style | VERTEX BELOW CENTER |
| Cross-Sectional Shape Style | CHAMFERED OUTSIDE CORNERS |
| Outside Diameter | 3.720 INCHES NOMINAL IN |
| Major Thickness | 0.078 INCHES MINIMUM AND 0.082 INCHES MAXIMUM IN |
| Inside Diameter | 3.400 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 |
|---|---|
| AS4570-81 | Bsi Standards Limited (GBR) |
| Reference | Meaning |
|---|---|
| AS4570-81 | 3/9 Design control — primary reference Metric and Multistandard Components Corp |
NSN 5325-01-340-4901 is a Ring,retaining, manufactured by Bsi Standards Limited, classified under FSC 5325, Fastening Devices. Status: active.
NSN 5325-01-340-4901 has 1 manufacturer part number on file: AS4570-81 (Bsi Standards Limited).
Key specifications for AS4570-81: Usage Design: EXTERNAL; End Style: VERTEX BELOW CENTER; Cross-Sectional Shape Style: CHAMFERED OUTSIDE CORNERS; Outside Diameter: 3.720 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.