PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

F5509ATee,tube to Boss

Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M · NSN 4730-00-278-2754 · FSC 4730 · No Item Name Available
Verified by PartsTable
NSN 4730-00-278-2754 — this item is cataloged by the U.S. Government under National Stock Number 4730-00-278-2754. Primary manufacturer part number: F5509A.
Features
  • Tee,tube to Boss — FSC 4730
  • Connection Style: GASKET SEAL (BOSS) SECOND END
  • Connection Type: THREADED EXTERNAL TUBE FIRST END
  • Nominal Outside Diameter Tube Accommodated: 0.625 INCHES THIRD END IN
  • Seat Angle: 37.0 DEGREES THIRD END
  • Connection Type: THREADED INTERNAL BOSS SECOND END
  • Connection Style: FLARED (TUBE) FIRST END
  • Leg Length: 1.156 INCHES NOMINAL SECOND END IN
Applications
  • Fluid conveyance
  • Hydraulic system plumbing
  • Pneumatic line routing
  • Applications requiring Steel Overall construction
General Description

The Tee,tube to Boss, cataloged under National Stock Number 4730-00-278-2754, is classified within Federal Supply Class 4730 (No Item Name Available) of the Pipe, Tubing, Hose, and Fittings group. The primary manufacturer of record is Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M. Government technical data includes 26 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 4 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: Cancelled.

Technical Specifications
ParameterValue
NSN4730-00-278-2754
Primary Part NumberF5509A
Item NameTee,tube to Boss
FSC / FSG4730 / 47 — No Item Name Available
ManufacturerMilitary Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
StatusCANCELLED
Connection StyleGASKET SEAL (BOSS) SECOND END
Connection TypeTHREADED EXTERNAL TUBE FIRST END
Nominal Outside Diameter Tube Accommodated0.625 INCHES THIRD END IN
Seat Angle37.0 DEGREES THIRD END
Connection TypeTHREADED INTERNAL BOSS SECOND END
Connection StyleFLARED (TUBE) FIRST END
Leg Length1.156 INCHES NOMINAL SECOND END IN
Thread Class3A FIRST END BULKHEAD A
Nominal Thread Size0.875 INCHES FIRST END BULKHEAD IN
Leg Length1.625 INCHES NOMINAL THIRD END IN
Thread Class3B SECOND END
Nominal Outside Diameter Tube Accommodated0.625 INCHES FIRST END IN
Thread Class3A FIRST END A
Nominal Thread Size0.875 INCHES ALL ENDS IN
Seat Angle37.0 DEGREES FIRST END
Connection StyleFLARED (TUBE) THIRD END
Leg Length2.375 INCHES NOMINAL FIRST END IN
Connection TypeTHREADED EXTERNAL TUBE THIRD END
Specification/standard Data88044-AN784 GOVERNMENT STANDARD
Thread Class3A THIRD END A
Thread Series DesignatorUNIFIED NATIONAL JOINT FINE (UNJF) FIRST END BULKHEAD
Surface Treatment Document and ClassificationQQ-P-416,TY 1,CL 2 FED SPEC SINGLE TREATMENT RESPONSE OUTSIDE
Surface Treatment Document and ClassificationQQ-P-416,TY 1,CL 2 FED SPEC SINGLE TREATMENT RESPONSE INSIDE
Surface TreatmentCADMIUM OVERALL
Thread Series DesignatorUNIFIED NATIONAL JOINT FINE (UNJF) ALL ENDS
MaterialSTEEL OVERALL
Lifecycle & Compliance
Acquisition StatusCANCELLED
HAZMATNo
Verified Substitutes 3
4730-00-555-2889AS5195R0602 INTERCHANGEABLE
Elbow,pipe to Tube
Sae International Dba Sae International
4730-00-640-5835 INTERCHANGEABLE
Tee,tube
4730-00-702-5694AS4862-03 INTERCHANGEABLE
Plug,pipe
Sae International Dba Sae International
Cross-Reference Index
Part NumberManufacturer
F5509A Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
MIL-F-5509 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
AN826-7D Aeronautical Standards Group Dept of Navy and Air Force (USA)
AN784-10 Aeronautical Standards Group Dept of Navy and Air Force (USA)
Related Parts
4730-00-555-2889INTERCHANGEABLE
ELBOW,PIPE TO TUBE
AS5195R0602
4730-00-640-5835INTERCHANGEABLE
TEE,TUBE
4730-00-702-5694INTERCHANGEABLE
PLUG,PIPE
AS4862-03

Frequently Asked Questions

What is NSN 4730-00-278-2754?

NSN 4730-00-278-2754 is a Tee,tube to Boss, manufactured by Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M, classified under FSC 4730 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 4730-00-278-2754?

NSN 4730-00-278-2754 has 4 cross-referenced part numbers: F5509A (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), MIL-F-5509 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), AN826-7D (Aeronautical Standards Group Dept of Navy and Air Force), AN784-10 (Aeronautical Standards Group Dept of Navy and Air Force).

What NSN replaces 4730-00-278-2754?

There are 3 known substitutes for 4730-00-278-2754: 4730-00-555-2889, 4730-00-640-5835, 4730-00-702-5694. Verify interchangeability with system specifications before substitution.

What are the specifications of F5509A?

Key specifications for F5509A: Connection Style: GASKET SEAL (BOSS) SECOND END; Connection Type: THREADED EXTERNAL TUBE FIRST END; Nominal Outside Diameter Tube Accommodated: 0.625 INCHES THIRD END IN; Seat Angle: 37.0 DEGREES THIRD END. 26 total characteristics are documented in the Federal Logistics Information System.

Is NSN 4730-00-278-2754 still in active supply?

NSN 4730-00-278-2754 is currently cancelled. Check with the Defense Logistics Agency for current availability and authorized substitutes.

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