The Screw Hairspring, cataloged under National Stock Number 6645-00-474-4957, is classified within Federal Supply Class 6645 (Time Measuring Instruments) of the Instruments and Laboratory Equipment group. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 1 item shares a part number with this NSN in the catalog (possible match — not a government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.
| Item Name | Screw Hairspring |
| FSC / FSG | 6645 — Time Measuring Instruments (FSG 66) |
| Parameter | Value |
|---|---|
| NSN | 6645-00-474-4957 |
| Item Name | Screw Hairspring |
| FSC / FSG | 6645 / 66 — Time Measuring Instruments |
| Status | ACTIVE |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Reference | Meaning |
|---|---|
| 146-3260 | 3/9 Design control — primary reference Elgin National Industries Inc |
NSN 6645-00-474-4957 is a Screw Hairspring, classified under FSC 6645, Time Measuring Instruments. Status: active.
1 possible match (shared part number, not a government interchangeability claim): 5365-01-225-1330. Verify interchangeability with system specifications before substitution.
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.