NSN 1680-01-100-4965 — this item is cataloged by the U.S. Government under National Stock Number 1680-01-100-4965. Manufacturer of record part number: 21243.
Also searched as1680-01-100-4965 ·
1680011004965 ·
NIIN 011004965 ·
01-100-4965 ·
FSC 1680 Miscellaneous Aircraft Accessories and Components · CAGE 30377 · 21243
Nearby stock numbers← 1680-01-100-4963 Stiffener Bar
·
1680-01-100-4970 →
Features
Crystal Block — FSC 1680
General Characteristics Item Description: MATERIAL AL ALLOY 2024-T351; FINIISH CHEMICAL FILM MIL-C-5541 CL 1A; LG 1.100 IN. NOM; WIDTH 0.700 IN. NOM,3HOLES 2/0.086/-56 UNC-2B,2 HOLES 0.125 DIA,APERTURE LG 0.725 IN. NOM; APERTURE WIDTH 0.575 IN. NOM A
1 manufacturer part number on file
Manufacturer of record: Smiths Aerospace, Inc., Electronic Systems-Grand Rapids
Identification
NSN: 1680-01-100-4965
NIIN: 011004965
FSC: 1680 — Miscellaneous Aircraft Accessories and Components
The Crystal Block, cataloged under National Stock Number 1680-01-100-4965, is classified within Federal Supply Class 1680 (Miscellaneous Aircraft Accessories and Components) of the Aircraft Components and Accessories group. The manufacturer of record is Smiths Aerospace, Inc., Electronic Systems-Grand Rapids. Government technical data includes 1 specification, 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. 8 items share a part number with this NSN in the catalog (possible match — not a government interchangeability claim). Current acquisition status: Active.
Technical Specifications
Parameter
Value
NSN
1680-01-100-4965
Primary Part Number
21243
Item Name
Crystal Block
FSC / FSG
1680 / 16 — Miscellaneous Aircraft Accessories and Components
MATERIAL AL ALLOY 2024-T351; FINIISH CHEMICAL FILM MIL-C-5541 CL 1A; LG 1.100 IN. NOM; WIDTH 0.700 IN. NOM,3HOLES 2/0.086/-56 UNC-2B,2 HOLES 0.125 DIA,APERTURE LG 0.725 IN. NOM; APERTURE WIDTH 0.575 IN. NOM A
Lifecycle & Compliance
Acquisition Status
ACTIVE
DEMIL Code
DEMIL B — Remove Demilitarization Key Points
Hazard
No hazard code in the DLA record (HMIC N)
Criticality Code
X
⇄Related Items8
Each row states its source: a government interchangeability/replacement code, or a possible match on a shared part number.
3040-01-391-082921243-11POSSIBLE MATCH
LEVER,MANUAL CONTROL
Possible match (shared part number)Rockwell Collins Inc
4820-01-414-804021241-1003-1POSSIBLE MATCH
SEAT,VALVE
Possible match (shared part number)Sargent Aerospace & Defense, Llc Dba Sargent Controls & Aerospace Div Sargent Controls & Aerospace
4820-01-415-103721241-1002-1POSSIBLE MATCH
CAP,VALVE
Possible match (shared part number)Sargent Aerospace & Defense, Llc Dba Sargent Controls & Aerospace Div Sargent Controls & Aerospace
4820-01-415-259321241-1000-1POSSIBLE MATCH
STEM,FLUID VALVE
Possible match (shared part number)Sargent Aerospace & Defense, Llc Dba Sargent Controls & Aerospace Div Sargent Controls & Aerospace
4820-01-415-259621241-1004-1POSSIBLE MATCH
KEEPER,VALVE
Possible match (shared part number)Sargent Aerospace & Defense, Llc Dba Sargent Controls & Aerospace Div Sargent Controls & Aerospace
4820-01-415-438621243-001POSSIBLE MATCH
VALVE,RESTRICTOR CHECK
Possible match (shared part number)Sargent Aerospace & Defense, Llc Dba Sargent Controls & Aerospace Div Sargent Controls & Aerospace
5310-01-474-918221241-1006-1POSSIBLE MATCH
WASHER,FLAT
Possible match (shared part number)Sargent Aerospace & Defense, Llc Dba Sargent Controls & Aerospace Div Sargent Controls & Aerospace
4320-01-484-046421243POSSIBLE MATCH
HOUSING,HYDRAULIC MOTOR,NON AIRC
Possible match (shared part number)Parker Hannifin Corporation Div Hydraulic Systems Division
NSN 1680-01-100-4965 is a Crystal Block, manufactured by Smiths Aerospace, Inc., Electronic Systems-Grand Rapids, classified under FSC 1680, Miscellaneous Aircraft Accessories and Components. Status: active.
What part numbers are listed for NSN 1680-01-100-4965?
NSN 1680-01-100-4965 has 1 manufacturer part number on file: 21243 (Smiths Aerospace, Inc., Electronic Systems-Grand Rapids).
What NSN replaces 1680-01-100-4965?
8 possible matches (shared part number, not a government interchangeability claim): 3040-01-391-0829, 4820-01-414-8040, 4820-01-415-1037. Verify interchangeability with system specifications before substitution.
What are the specifications of 21243?
Key specifications for 21243: General Characteristics Item Description: MATERIAL AL ALLOY 2024-T351; FINIISH CHEMICAL FILM MIL-C-5541 CL 1A; LG 1.100 IN. NOM; WIDTH 0.700 IN. NOM,3HOLES 2/0.086/-56 UNC-2B,2 HOLES 0.125 DIA,APERTURE LG 0.725 IN. NOM; APERTURE WIDTH 0.575 IN. NOM A. 1 specification is documented in the U.S. Government catalog.
Is NSN 1680-01-100-4965 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.
What is the DEMIL code for NSN 1680-01-100-4965?
NSN 1680-01-100-4965 has DEMIL Code B. Demilitarization may be required before disposal or transfer to non-military entities.
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.