The Ring,retaining,optical Element, cataloged under National Stock Number 1240-01-291-7137, is classified within Federal Supply Class 1240 (Optical Sighting and Ranging Equipment) of the Fire Control Equipment group. The manufacturer of record is Lockheed Martin Corporation. Government technical data includes 12 specifications, cited from the U.S. Government catalog. The record lists 2 manufacturer part numbers 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through both NSN and commercial part number lookups. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog.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 | 1240-01-291-7137 |
| Primary Part Number | 717511336-009 |
| Item Name | Ring,retaining,optical Element |
| FSC / FSG | 1240 / 12 — Optical Sighting and Ranging Equipment |
| Manufacturer | Lockheed Martin Corporation |
| Status | ACTIVE |
| Groove Location | ADJACENT TO INTERNAL FLANGE |
| Internal Flange Thickness | 0.063 INCHES NOMINAL IN |
| Groove Diameter | 4.180 INCHES NOMINAL IN |
| Thread Pitch Diameters | +4.1313 TO 4.1700 INCHES IN |
| Outside Diameter | 4.290 INCHES NOMINAL IN |
| Thread Location | INTERNAL |
| Aperture Diameter | 3.917 INCHES NOMINAL IN |
| Thread Direction | RIGHT-HAND |
| Inner Groove Width | 0.0500 INCHES NOMINAL IN |
| Thread Size | 4 11/64-28 |
| Screw Thread Series Designator | UNS |
| Thread Class | 2B |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL B — Remove Demilitarization Key Points |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | X |
| Part Number | Manufacturer |
|---|---|
| 717511336-009 | Vital Engineered Components Company, Inc. (USA) |
| 717511336-009 PRIMARY | Lockheed Martin Corporation (USA) |
| Reference | Meaning |
|---|---|
| 717511333-001 | 5/9 Secondary reference Lockheed Martin Corporation |
NSN 1240-01-291-7137 is a Ring,retaining,optical Element, manufactured by Lockheed Martin Corporation, classified under FSC 1240, Optical Sighting and Ranging Equipment. Status: active.
NSN 1240-01-291-7137 has 2 manufacturer part numbers on file: 717511336-009 (Vital Engineered Components Company, Inc.), 717511336-009 (Lockheed Martin Corporation).
Key specifications for 717511336-009: Groove Location: ADJACENT TO INTERNAL FLANGE; Internal Flange Thickness: 0.063 INCHES NOMINAL IN; Groove Diameter: 4.180 INCHES NOMINAL IN; Thread Pitch Diameters: +4.1313 TO 4.1700 INCHES IN. 12 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.
NSN 1240-01-291-7137 has DEMIL Code B. Demilitarization may be required before disposal or transfer to non-military entities.
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.