The Clock,panel, cataloged under National Stock Number 6645-01-129-3954, is classified within Federal Supply Class 6645 (Time Measuring Instruments) of the Instruments and Laboratory Equipment group. The manufacturer of record is Waltham Aircraft Clock Corp. The record lists 1 manufacturer part number for this item, enabling identification through both NSN and commercial part number lookups. 2 additional reference documents (drawings, advisory and superseded references) are recorded in the U.S. Government catalog. 2 items share a part number with this NSN in the catalog (possible match — not a government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 | 6645-01-129-3954 |
| Primary Part Number | 400257 |
| Item Name | Clock,panel |
| FSC / FSG | 6645 / 66 — Time Measuring Instruments |
| Manufacturer | Waltham Aircraft Clock Corp |
| Status | ACTIVE |
| Acquisition Status | ACTIVE |
| DEMIL Code | DEMIL A — No Demilitarization Required |
| Hazard | No hazard code in the DLA record (HMIC N) |
| Criticality Code | N |
| Part Number | Manufacturer |
|---|---|
| 400257 PRIMARY | Waltham Aircraft Clock Corp (USA) |
| Reference | Meaning |
|---|---|
| 400257 | 5/9 Secondary reference Waltham Clock Co Inc |
| ABU-24/A | 5/1 Secondary reference U.S. Government activity |
NSN 6645-01-129-3954 is a Clock,panel, manufactured by Waltham Aircraft Clock Corp, classified under FSC 6645, Time Measuring Instruments. Status: active.
NSN 6645-01-129-3954 has 1 manufacturer part number on file: 400257 (Waltham Aircraft Clock Corp).
2 possible matches (shared part number, not a government interchangeability claim): 4820-01-208-5591, 3040-01-283-5030. Verify interchangeability with system specifications before substitution.
Key specifications for 400257: Overall Height: 2.375 INCHES NOMINAL IN; Overall Width: 2.375 INCHES NOMINAL IN; Part Name Assigned by Controlling Agency: CLOCK,AIRCRAFT,MECHANICAL. 0 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.