NSN 6685-01-020-5635 · NIIN 010205635 · Part number 4551-21
Siemens Industry, Inc. Dba Siemens Energy Div Process Industries and Drives · FSC 6685 — Pressure, Temperature, and Humidity Measuring and Controlling Instruments · FSG 66 — Instruments and Laboratory Equipment · CAGE 41387
Government record, cited
NSN 6685-01-020-5635 — this item is cataloged by the U.S. Government under National Stock Number 6685-01-020-5635. Manufacturer of record part number: 4551-21.
Also searched as6685-01-020-5635 ·
6685010205635 ·
NIIN 010205635 ·
01-020-5635 ·
FSC 6685 Pressure, Temperature, and Humidity Measuring and Controlling Instruments · CAGE 41387 · 4551-21 · 4551-21-G
General Characteristics Item Description: DOWEL TUBE 2,DIAPHRAGM 6,SPACER 5
2 manufacturer part numbers on file
Manufacturer of record: Siemens Industry, Inc. Dba Siemens Energy Div Process Industries and Drives
Identification
NSN: 6685-01-020-5635
NIIN: 010205635
FSC: 6685 — Pressure, Temperature, and Humidity Measuring and Controlling Instruments
FSG: 66 — Instruments and Laboratory Equipment
Primary part number: 4551-21
Manufacturer: Siemens Industry, Inc. Dba Siemens Energy Div Process Industries and Drives
General Description
The Diaphragm Assembly, cataloged under National Stock Number 6685-01-020-5635, is classified within Federal Supply Class 6685 (Pressure, Temperature, and Humidity Measuring and Controlling Instruments) of the Instruments and Laboratory Equipment group. The manufacturer of record is Siemens Industry, Inc. Dba Siemens Energy Div Process Industries and Drives. Government technical data includes 1 specification, 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. Current acquisition status: Active.
Technical Specifications
Parameter
Value
NSN
6685-01-020-5635
Primary Part Number
4551-21
Item Name
Diaphragm Assembly
FSC / FSG
6685 / 66 — Pressure, Temperature, and Humidity Measuring and Controlling Instruments
Manufacturer
Siemens Industry, Inc. Dba Siemens Energy Div Process Industries and Drives
Status
ACTIVE
General Characteristics Item Description
DOWEL TUBE 2,DIAPHRAGM 6,SPACER 5
Lifecycle & Compliance
Acquisition Status
ACTIVE
DEMIL Code
DEMIL A — No Demilitarization Required
Hazard
Possible hazard — SDS may be required (DLA HMIC P)
Siemens Industry, Inc. Dba Siemens Energy Div Process Industries and Drives (USA)
No interchangeability data on file.
Other items in FSC 6685 — Pressure, Temperature, and Humidity Measuring and Controlling Instruments
Items in the same Federal Supply class. No interchangeability or substitution relationship is implied.
6685-00-001-1475
6685-00-001-1475 · Item name not on file
6685-00-001-1503
CONTROL,TOTALIZER
6685-00-001-1643
6685-00-001-1643 · Item name not on file
6685-00-001-1711
GAGE,PRESSURE,DIAL INDICATING
6685-00-001-2099
6685-00-001-2099 · Item name not on file
6685-00-001-2100
6685-00-001-2100 · Item name not on file
6685-00-001-2101
6685-00-001-2101 · Item name not on file
6685-00-001-2102
6685-00-001-2102 · Item name not on file
Frequently Asked Questions
What is NSN 6685-01-020-5635?
NSN 6685-01-020-5635 is a Diaphragm Assembly, manufactured by Siemens Industry, Inc. Dba Siemens Energy Div Process Industries and Drives, classified under FSC 6685, Pressure, Temperature, and Humidity Measuring and Controlling Instruments. Status: active.
What part numbers are listed for NSN 6685-01-020-5635?
NSN 6685-01-020-5635 has 2 manufacturer part numbers on file: 4551-21 (Siemens Industry, Inc. Dba Siemens Energy Div Process Industries and Drives), 4551-21-G (Siemens Industry, Inc. Dba Siemens Energy Div Process Industries and Drives).
What are the specifications of 4551-21?
Key specifications for 4551-21: General Characteristics Item Description: DOWEL TUBE 2,DIAPHRAGM 6,SPACER 5; End Item Identification: BOILERS,1200 PSI;MAIN FEED PUMPS; POSEIDON MATERIAL;PROPULSION SYSTEMS. 1 specification is documented in the U.S. Government catalog.
Is NSN 6685-01-020-5635 hazardous material?
Possible hazard — SDS may be required (DLA HMIC P). 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.