PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

866Seat,valve

Lawler Manufacturing Company, Inc. · NSN 4820-00-399-2762 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-399-2762 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-399-2762. Primary manufacturer part number: 866.
Features
  • Seat,valve — FSC 4820
  • Seating Surface Shape: ANGULAR
  • Seat Angle in Deg: 58.000 NOMINAL
  • Thread Length: 0.375 INCHES NOMINAL SINGLE THREADED PORTION IN
  • Style Designator: THREADED FLANGED
  • Material: STEEL CORROSION RESISTING OVERALL
  • Flange Seat to Disk End Height: 0.375 INCHES NOMINAL IN
  • Thread Quantity Per Inch: 20 SINGLE THREADED PORTION
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Steel Corrosion Resisting Overall construction
General Description

The Seat,valve, cataloged under National Stock Number 4820-00-399-2762, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Lawler Manufacturing Company, Inc.. Government technical data includes 13 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 1 commercial cross-reference from 1 manufacturer, enabling identification through both NSN and commercial part number lookups. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-00-399-2762
Primary Part Number866
Item NameSeat,valve
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerLawler Manufacturing Company, Inc.
StatusACTIVE
Seating Surface ShapeANGULAR
Seat Angle in Deg58.000 NOMINAL
Thread Length0.375 INCHES NOMINAL SINGLE THREADED PORTION IN
Style DesignatorTHREADED FLANGED
MaterialSTEEL CORROSION RESISTING OVERALL
Flange Seat to Disk End Height0.375 INCHES NOMINAL IN
Thread Quantity Per Inch20 SINGLE THREADED PORTION
Thread Series DesignatorUN SINGLE THREADED PORTION
Thread Class2A SINGLE THREADED PORTION A
Under Flange Height0.375 INCHES NOMINAL IN
Nominal Thread Size1.125 INCHES SINGLE THREADED PORTION IN
Body Inside Diameter0.750 INCHES NOMINAL IN
Flange Diameter1.250 INCHES NOMINAL IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 12
3110-00-101-0998866 INTERCHANGEABLE
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5120-00-133-1782 INTERCHANGEABLE
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6130-00-214-8224886 INTERCHANGEABLE
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5975-00-284-8837101D INTERCHANGEABLE
Cover,junction Box
Ni Industries Inc Bowers Mfg Co Div
2805-00-361-2263V961 INTERCHANGEABLE
Valve,poppet,engine
Eaton Corp Dba Eaton Aerospace Jackson
6115-00-529-6791S18577 INTERCHANGEABLE
Converter,thermal Watt
H20 Tank Inc U S Motors Div
6625-00-553-8413TS452PARENU INTERCHANGEABLE
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5950-00-755-0004 INTERCHANGEABLE
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3110-00-837-12864909027 INTERCHANGEABLE
Ring,bearing,inner
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Cross-Reference Index
Part NumberManufacturer
866 PRIMARY Lawler Manufacturing Company, Inc. (USA)
Related Parts
3110-00-101-0998INTERCHANGEABLE
CONE AND ROLLERS,TAPERED ROLLER
866
5120-00-133-1782INTERCHANGEABLE
CONTACT POSITIONER,TERMINAL CRIM
6130-00-214-8224INTERCHANGEABLE
CONVERTER,WATT
886
5940-00-237-6728INTERCHANGEABLE
TERMINAL BOARD
56A
5975-00-284-8837INTERCHANGEABLE
COVER,JUNCTION BOX
101D
2805-00-361-2263INTERCHANGEABLE
VALVE,POPPET,ENGINE
V961
6115-00-529-6791INTERCHANGEABLE
CONVERTER,THERMAL WATT
S18577
6625-00-553-8413INTERCHANGEABLE
GENERATOR,SIGNAL
TS452PARENU
5950-00-755-0004INTERCHANGEABLE
COIL,RADIO FREQUENCY
3110-00-837-1286INTERCHANGEABLE
RING,BEARING,INNER
4909027
5940-00-842-2917INTERCHANGEABLE
TERMINAL BOARD
707-5020
5140-01-047-3588INTERCHANGEABLE
TOOL BOX,PORTABLE
2-517

Frequently Asked Questions

What is NSN 4820-00-399-2762?

NSN 4820-00-399-2762 is a Seat,valve, manufactured by Lawler Manufacturing Company, Inc., classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-00-399-2762?

NSN 4820-00-399-2762 has 1 cross-referenced part number: 866 (Lawler Manufacturing Company, Inc.).

What NSN replaces 4820-00-399-2762?

There are 12 known substitutes for 4820-00-399-2762: 3110-00-101-0998, 5120-00-133-1782, 6130-00-214-8224 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of 866?

Key specifications for 866: Seating Surface Shape: ANGULAR; Seat Angle in Deg: 58.000 NOMINAL; Thread Length: 0.375 INCHES NOMINAL SINGLE THREADED PORTION IN; Style Designator: THREADED FLANGED. 13 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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