PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

B16.39Union,pipe

The American Society of Mechanical Engineers · NSN 4730-00-189-2646 · FSC 4730 · No Item Name Available
Verified by PartsTable
NSN 4730-00-189-2646 — this item is cataloged by the U.S. Government under National Stock Number 4730-00-189-2646. Primary manufacturer part number: B16.39.
Features
  • Union,pipe — FSC 4730
  • Surface Treatment: ZINC OVERALL
  • Surface Treatment: ZINC OVERALL
  • Specification/standard Data: 81349-MIL-U-18250 GOVERNMENT SPECIFICATION
  • Nondefinitive Spec/std Data: XD TYPE
  • Reducer Type: CONCENTRIC
  • Nominal Thread Size: 0.500 INCHES ALL ENDS IN
  • Specification/standard Data: 81349-MIL-U-18250 GOVERNMENT SPECIFICATION
Applications
  • Fluid conveyance
  • Hydraulic system plumbing
  • Pneumatic line routing
  • Applications requiring Steel or Iron Overall construction
General Description

The Union,pipe, cataloged under National Stock Number 4730-00-189-2646, 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 The American Society of Mechanical Engineers. Government technical data includes 27 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. 12 verified substitutes exist in the FLIS interchangeability database. Current acquisition status: Active.

Technical Specifications
ParameterValue
NSN4730-00-189-2646
Primary Part NumberB16.39
Item NameUnion,pipe
FSC / FSG4730 / 47 — No Item Name Available
ManufacturerThe American Society of Mechanical Engineers
StatusACTIVE
Surface TreatmentZINC OVERALL
Surface TreatmentZINC OVERALL
Specification/standard Data81349-MIL-U-18250 GOVERNMENT SPECIFICATION
Nondefinitive Spec/std DataXD TYPE
Reducer TypeCONCENTRIC
Nominal Thread Size0.500 INCHES ALL ENDS IN
Specification/standard Data81349-MIL-U-18250 GOVERNMENT SPECIFICATION
Style DesignatorSCREWED
Media for Which DesignedWATER-OIL-GAS SINGLE RESPONSE
Coupling Flange ShapeHEXAGON
Operating Pressure300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
MaterialSTEEL OR IRON OVERALL
Seat TypeGROUND-JOINT
Connection TypeTHREADED INTERNAL PIPE ALL ENDS
Nominal Overall Length1.930 INCHES IN
Seat TypeGROUND-JOINT
MaterialSTEEL OR IRON OVERALL
Thread Series DesignatorNPT ALL ENDS
Connection StylePLAIN (PIPE) ALL ENDS
Nominal Overall Length1.930 INCHES IN
Operating Pressure300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
Nominal Thread Size0.500 INCHES ALL ENDS IN
Nondefinitive Spec/std DataXD TYPE
Thread Series DesignatorNPT ALL ENDS
Media for Which DesignedWATER-OIL-GAS SINGLE RESPONSE
Style DesignatorSCREWED
Coupling Flange ShapeHEXAGON
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 12
4730-00-189-2598 INTERCHANGEABLE
Union,pipe
4730-00-189-2599 INTERCHANGEABLE
Union,pipe
4730-00-189-2600 INTERCHANGEABLE
Union,pipe
4730-00-189-26021631-400 INTERCHANGEABLE
Union,pipe
Flaton Machine Works Inc.
4730-00-189-2605 INTERCHANGEABLE
Union,pipe
4730-00-189-2606 INTERCHANGEABLE
Union,pipe
4730-00-189-2629 INTERCHANGEABLE
Union,pipe
4730-00-189-2630 INTERCHANGEABLE
Union,pipe
4730-00-189-2635 INTERCHANGEABLE
Union,pipe
4730-00-189-2638 INTERCHANGEABLE
Union,pipe
Cross-Reference Index
Part NumberManufacturer
B16.39 The American Society of Mechanical Engineers (USA)
MILU18250 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
Related Parts
4730-00-189-2598INTERCHANGEABLE
UNION,PIPE
4730-00-189-2599INTERCHANGEABLE
UNION,PIPE
4730-00-189-2600INTERCHANGEABLE
UNION,PIPE
4730-00-189-2602INTERCHANGEABLE
UNION,PIPE
1631-400
4730-00-189-2605INTERCHANGEABLE
UNION,PIPE
4730-00-189-2606INTERCHANGEABLE
UNION,PIPE
4730-00-189-2629INTERCHANGEABLE
UNION,PIPE
4730-00-189-2630INTERCHANGEABLE
UNION,PIPE
4730-00-189-2635INTERCHANGEABLE
UNION,PIPE
4730-00-189-2638INTERCHANGEABLE
UNION,PIPE
4730-00-189-2639INTERCHANGEABLE
UNION,PIPE
4730-00-189-2645INTERCHANGEABLE
UNION,PIPE

Frequently Asked Questions

What is NSN 4730-00-189-2646?

NSN 4730-00-189-2646 is a Union,pipe, manufactured by The American Society of Mechanical Engineers, classified under FSC 4730 (No Item Name Available). Status: active.

What are the part numbers for NSN 4730-00-189-2646?

NSN 4730-00-189-2646 has 2 cross-referenced part numbers: B16.39 (The American Society of Mechanical Engineers), MILU18250 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M).

What NSN replaces 4730-00-189-2646?

There are 12 known substitutes for 4730-00-189-2646: 4730-00-189-2598, 4730-00-189-2599, 4730-00-189-2600 and 9 more. Verify interchangeability with system specifications before substitution.

What are the specifications of B16.39?

Key specifications for B16.39: Surface Treatment: ZINC OVERALL; Surface Treatment: ZINC OVERALL; Specification/standard Data: 81349-MIL-U-18250 GOVERNMENT SPECIFICATION; Nondefinitive Spec/std Data: XD TYPE. 27 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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