PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

525-25Seat,valve

Ontic Engineering & Manufacturing, Inc Dba Ontic Us · NSN 4820-00-486-3400 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-486-3400 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-486-3400. Primary manufacturer part number: 525-25.
Features
  • Seat,valve — FSC 4820
  • Body Inside Diameter: 0.312 INCHES MINIMUM AND 0.313 INCHES MAXIMUM IN
  • FSC Application Data: ACFT PROPELLER FEATHERING PUMP
  • Material: STEEL OVERALL
  • Surface Treatment: CADMIUM OVERALL
  • Hardness Rating: 45.0 ROCKWELL C MINIMUM AND 50.0 ROCKWELL C MAXIMUM BODY
  • Material Document and Classification: SAE 52100 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
  • Seating Surface Shape: FLAT
Applications
  • Flow control in piping systems
  • Pressure regulation
  • Steam and fluid isolation
  • Applications requiring Steel Overall construction
General Description

The Seat,valve, cataloged under National Stock Number 4820-00-486-3400, is classified within Federal Supply Class 4820 (No Item Name Available) of the Valves group. The primary manufacturer of record is Ontic Engineering & Manufacturing, Inc Dba Ontic Us. Government technical data includes 11 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 2 commercial cross-references from 2 manufacturers, 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
NSN4820-00-486-3400
Primary Part Number525-25
Item NameSeat,valve
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerOntic Engineering & Manufacturing, Inc Dba Ontic Us
StatusACTIVE
Body Inside Diameter0.312 INCHES MINIMUM AND 0.313 INCHES MAXIMUM IN
FSC Application DataACFT PROPELLER FEATHERING PUMP
MaterialSTEEL OVERALL
Surface TreatmentCADMIUM OVERALL
Hardness Rating45.0 ROCKWELL C MINIMUM AND 50.0 ROCKWELL C MAXIMUM BODY
Material Document and ClassificationSAE 52100 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
Seating Surface ShapeFLAT
Body Outside Diameter0.570 INCHES MINIMUM AND 0.572 INCHES MAXIMUM IN
Flange Seat to Disk End Height0.250 INCHES NOMINAL IN
Seal Accommodation TypeGROOVED
Under Flange Height0.969 INCHES NOMINAL IN
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 3
4730-00-020-26475252-5 INTERCHANGEABLE
Restrictor,fluid Flow
Goodrich Aerospace Canada Ltd
3455-00-140-3043 INTERCHANGEABLE
File,rotary
6680-01-111-869852525 INTERCHANGEABLE
Transmitter,liquid Quantity
Setra Systems, Inc. Dba Gems Sensors
Cross-Reference Index
Part NumberManufacturer
525-25 Donallco Inc (USA)
525-25 PRIMARY Ontic Engineering & Manufacturing, Inc Dba Ontic Us (USA)
Related Parts
4730-00-020-2647INTERCHANGEABLE
RESTRICTOR,FLUID FLOW
5252-5
3455-00-140-3043INTERCHANGEABLE
FILE,ROTARY
6680-01-111-8698INTERCHANGEABLE
TRANSMITTER,LIQUID QUANTITY
52525

Frequently Asked Questions

What is NSN 4820-00-486-3400?

NSN 4820-00-486-3400 is a Seat,valve, manufactured by Ontic Engineering & Manufacturing, Inc Dba Ontic Us, classified under FSC 4820 (No Item Name Available). Status: active.

What are the part numbers for NSN 4820-00-486-3400?

NSN 4820-00-486-3400 has 2 cross-referenced part numbers: 525-25 (Donallco Inc), 525-25 (Ontic Engineering & Manufacturing, Inc Dba Ontic Us).

What NSN replaces 4820-00-486-3400?

There are 3 known substitutes for 4820-00-486-3400: 4730-00-020-2647, 3455-00-140-3043, 6680-01-111-8698. Verify interchangeability with system specifications before substitution.

What are the specifications of 525-25?

Key specifications for 525-25: Body Inside Diameter: 0.312 INCHES MINIMUM AND 0.313 INCHES MAXIMUM IN; FSC Application Data: ACFT PROPELLER FEATHERING PUMP; Material: STEEL OVERALL; Surface Treatment: CADMIUM OVERALL. 11 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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