PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

252-5ASeat,valve

Ontic Engineering & Manufacturing, Inc Dba Ontic Us · NSN 4820-00-533-3969 · FSC 4820 · No Item Name Available
Verified by PartsTable
NSN 4820-00-533-3969 — this item is cataloged by the U.S. Government under National Stock Number 4820-00-533-3969. Primary manufacturer part number: 252-5A.
Features
  • Seat,valve — FSC 4820
  • Seating Surface Shape: FLAT
  • Style Designator: PLAIN
  • Hardness Rating: 30.0 ROCKWELL C MINIMUM AND 35.0 ROCKWELL C MAXIMUM BODY
  • Material Document and Classification: AISI 8720 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
  • FSC Application Data: PUMP,ROTART,HYDRAULIC SYSTEM,AIRCRAFT
  • Material: STEEL OVERALL
  • Body Inside Diameter: 0.187 INCHES MINIMUM AND 0.189 INCHES MAXIMUM IN
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 4820-00-533-3969, 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 9 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. 2 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4820-00-533-3969
Primary Part Number252-5A
Item NameSeat,valve
FSC / FSG4820 / 48 — No Item Name Available
ManufacturerOntic Engineering & Manufacturing, Inc Dba Ontic Us
StatusACTIVE
Seating Surface ShapeFLAT
Style DesignatorPLAIN
Hardness Rating30.0 ROCKWELL C MINIMUM AND 35.0 ROCKWELL C MAXIMUM BODY
Material Document and ClassificationAISI 8720 ASSN STD SINGLE MATERIAL RESPONSE OVERALL
FSC Application DataPUMP,ROTART,HYDRAULIC SYSTEM,AIRCRAFT
MaterialSTEEL OVERALL
Body Inside Diameter0.187 INCHES MINIMUM AND 0.189 INCHES MAXIMUM IN
Body Outside Diameter0.314 INCHES MINIMUM AND 0.315 INCHES MAXIMUM IN
Surface TreatmentOXIDE OVERALL
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 2
1650-00-222-4525 INTERCHANGEABLE
Cap,valve
2520-00-802-41031-1275 INTERCHANGEABLE
Spider,universal Joint,vehicular
Neapco Inc
Cross-Reference Index
Part NumberManufacturer
252-5A PRIMARY Ontic Engineering & Manufacturing, Inc Dba Ontic Us (USA)
252-5A Donallco Inc (USA)
Related Parts
1650-00-222-4525INTERCHANGEABLE
CAP,VALVE
2520-00-802-4103INTERCHANGEABLE
SPIDER,UNIVERSAL JOINT,VEHICULAR
1-1275

Frequently Asked Questions

What is NSN 4820-00-533-3969?

NSN 4820-00-533-3969 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 4820-00-533-3969?

NSN 4820-00-533-3969 has 2 cross-referenced part numbers: 252-5A (Ontic Engineering & Manufacturing, Inc Dba Ontic Us), 252-5A (Donallco Inc).

What NSN replaces 4820-00-533-3969?

There are 2 known substitutes for 4820-00-533-3969: 1650-00-222-4525, 2520-00-802-4103. Verify interchangeability with system specifications before substitution.

What are the specifications of 252-5A?

Key specifications for 252-5A: Seating Surface Shape: FLAT; Style Designator: PLAIN; Hardness Rating: 30.0 ROCKWELL C MINIMUM AND 35.0 ROCKWELL C MAXIMUM BODY; Material Document and Classification: AISI 8720 ASSN STD SINGLE MATERIAL RESPONSE OVERALL. 10 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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