PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

166AThermostat,flow Control

Mack Trucks, Inc. Dba Macungie Operations Div Lehigh Valley Operations · NSN 6685-01-189-8214 · FSC 6685 · No Item Name Available
Verified by PartsTable
NSN 6685-01-189-8214 — this item is cataloged by the U.S. Government under National Stock Number 6685-01-189-8214. Primary manufacturer part number: 166A.
Features
  • Thermostat,flow Control — FSC 6685
  • FSC Application Data: ENGINE
  • 3 verified cross-references
  • Primary manufacturer: Mack Trucks, Inc. Dba Macungie Operations Div Lehigh Valley Operations
Applications
  • Industrial maintenance and repair
  • Government and military logistics
  • Equipment overhaul and refurbishment
General Description

The Thermostat,flow Control, cataloged under National Stock Number 6685-01-189-8214, is classified within Federal Supply Class 6685 (No Item Name Available) of the Instruments and Laboratory Equipment group. The primary manufacturer of record is Mack Trucks, Inc. Dba Macungie Operations Div Lehigh Valley Operations. Government technical data includes 1 verified specification, sourced from the Federal Logistics Information System (FLIS). This item has 3 commercial cross-references from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 3 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN6685-01-189-8214
Primary Part Number166A
Item NameThermostat,flow Control
FSC / FSG6685 / 66 — No Item Name Available
ManufacturerMack Trucks, Inc. Dba Macungie Operations Div Lehigh Valley Operations
StatusACTIVE
FSC Application DataENGINE
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 3
5120-00-224-7271166A INTERCHANGEABLE
Vise,pin
L.s. Starrett Company (the) Div Tool Division
4720-00-706-3983166A INTERCHANGEABLE
Hose
Brinkley Technology Group Llc Dba Hercules Manufacturing
4820-01-033-8464166A INTERCHANGEABLE
Valve,safety Relief
Stratotech Llc
Cross-Reference Index
Part NumberManufacturer
166A PRIMARY Mack Trucks, Inc. Dba Macungie Operations Div Lehigh Valley Operations (USA)
657GC38P55 Mack Trucks, Inc. Dba Macungie Operations Div Lehigh Valley Operations (USA)
215SB166P1 Mack Trucks, Inc. Dba Macungie Operations Div Lehigh Valley Operations (USA)
Related Parts
5120-00-224-7271INTERCHANGEABLE
VISE,PIN
166A
4720-00-706-3983INTERCHANGEABLE
HOSE
166A
4820-01-033-8464INTERCHANGEABLE
VALVE,SAFETY RELIEF
166A

Frequently Asked Questions

What is NSN 6685-01-189-8214?

NSN 6685-01-189-8214 is a Thermostat,flow Control, manufactured by Mack Trucks, Inc. Dba Macungie Operations Div Lehigh Valley Operations, classified under FSC 6685 (No Item Name Available). Status: active.

What are the part numbers for NSN 6685-01-189-8214?

NSN 6685-01-189-8214 has 3 cross-referenced part numbers: 166A (Mack Trucks, Inc. Dba Macungie Operations Div Lehigh Valley Operations), 657GC38P55 (Mack Trucks, Inc. Dba Macungie Operations Div Lehigh Valley Operations), 215SB166P1 (Mack Trucks, Inc. Dba Macungie Operations Div Lehigh Valley Operations).

What NSN replaces 6685-01-189-8214?

There are 3 known substitutes for 6685-01-189-8214: 5120-00-224-7271, 4720-00-706-3983, 4820-01-033-8464. Verify interchangeability with system specifications before substitution.

What are the specifications of 166A?

Key specifications for 166A: FSC Application Data: ENGINE. 1 total characteristics are documented in the Federal Logistics Information System.

Validated with multiple authoritative sources, including Government, OEM, and Certified sources.
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