The Hand,hour,clock, cataloged under National Stock Number 6645-00-787-0643, 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Instruments) of the Instruments and Laboratory Equipment group. 1 additional reference document (drawings, advisory and superseded references) is recorded in the U.S. Government catalog. 4 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
Catalog Facts
Item Name
Hand,hour,clock
FSC / FSG
6645 — Time Measuring Instruments (FSG 66)
Technical Specifications
Parameter
Value
NSN
6645-00-787-0643
Item Name
Hand,hour,clock
FSC / FSG
6645 / 66 — Time Measuring Instruments
Status
ACTIVE
Lifecycle & Compliance
Acquisition Status
ACTIVE
DEMIL Code
DEMIL A — No Demilitarization Required
Hazard
No hazard code in the DLA record (HMIC N)
⇄Related Items4
Each row states its source: a government interchangeability/replacement code, or a possible match on a shared part number.
3010-01-170-9283200331POSSIBLE MATCH
GEAR ASSEMBLY,SPEED DECREASER
Possible match (shared part number)Grove U.s. Llc Dba Grove Us Llc
6515-01-525-6066200-331POSSIBLE MATCH
PERFORATOR,CRANIAL
Possible match (shared part number)Acra Cut, Inc. Dba Acra-Cut Inc
6515-01-603-4587200-331POSSIBLE MATCH
DISSECTING TOOL,PNEUMATIC,ORTHOP
Possible match (shared part number)Medtronic Sofamor Danek Usa, Inc
1560-01-681-000520033.1POSSIBLE MATCH
PANEL,STRUCTURAL,AIRCRAFT
Possible match (shared part number)Kenjer Industries
Cross-Reference Index
No manufacturer part numbers on file in the U.S. Government catalog.
Reference documents
Reference
Meaning
200331
3/9Design control — primary reference
Waltham Clock Co Inc
Related Parts
3010-01-170-9283POSSIBLE MATCH
GEAR ASSEMBLY,SPEED DECREASER
200331
6515-01-525-6066POSSIBLE MATCH
PERFORATOR,CRANIAL
200-331
6515-01-603-4587POSSIBLE MATCH
DISSECTING TOOL,PNEUMATIC,ORTHOP
200-331
1560-01-681-0005POSSIBLE MATCH
PANEL,STRUCTURAL,AIRCRAFT
20033.1
Frequently Asked Questions
What is NSN 6645-00-787-0643?
NSN 6645-00-787-0643 is a Hand,hour,clock, classified under FSC 6645, Time Measuring Instruments. Status: active.
What NSN replaces 6645-00-787-0643?
4 possible matches (shared part number, not a government interchangeability claim): 3010-01-170-9283, 6515-01-525-6066, 6515-01-603-4587. Verify interchangeability with system specifications before substitution.
Is NSN 6645-00-787-0643 hazardous material?
No hazard code in the DLA record (HMIC N). Hazard information on this page is shown exactly as it appears in the DLA record.
Sources
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.
✓ Data cited from the U.S. Government catalog; commercial cross-references from OEM and certified industry sources.