PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

B16.39Union,pipe

The American Society of Mechanical Engineers · NSN 4730-00-189-2645 · FSC 4730 · No Item Name Available
Verified by PartsTable
NSN 4730-00-189-2645 — this item is cataloged by the U.S. Government under National Stock Number 4730-00-189-2645. Primary manufacturer part number: B16.39.
Features
  • Union,pipe — FSC 4730
  • Operating Pressure: 300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
  • Style Designator: SCREWED
  • Nondefinitive Spec/std Data: XD TYPE
  • Operating Pressure: 300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
  • Seat Type: GROUND-JOINT
  • Thread Series Designator: NPT ALL ENDS
  • Nominal Overall Length: 1.810 INCHES IN
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 4730-00-189-2645, 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 25 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: Cancelled.

Technical Specifications
ParameterValue
NSN4730-00-189-2645
Primary Part NumberB16.39
Item NameUnion,pipe
FSC / FSG4730 / 47 — No Item Name Available
ManufacturerThe American Society of Mechanical Engineers
StatusCANCELLED
Operating Pressure300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
Style DesignatorSCREWED
Nondefinitive Spec/std DataXD TYPE
Operating Pressure300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS
Seat TypeGROUND-JOINT
Thread Series DesignatorNPT ALL ENDS
Nominal Overall Length1.810 INCHES IN
Nominal Thread Size0.375 INCHES ALL ENDS IN
Coupling Flange ShapeHEXAGON
Specification/standard Data81349-MIL-U-18250 GOVERNMENT SPECIFICATION
Style DesignatorSCREWED
Seat TypeGROUND-JOINT
Reducer TypeCONCENTRIC
Connection TypeTHREADED INTERNAL PIPE ALL ENDS
Specification/standard Data81349-MIL-U-18250 GOVERNMENT SPECIFICATION
Surface TreatmentZINC OVERALL
Connection StylePLAIN (PIPE) ALL ENDS
MaterialSTEEL OR IRON OVERALL
Nominal Thread Size0.375 INCHES ALL ENDS IN
Coupling Flange ShapeHEXAGON
Nominal Overall Length1.810 INCHES IN
Surface TreatmentZINC OVERALL
MaterialSTEEL OR IRON OVERALL
Thread Series DesignatorNPT ALL ENDS
Nondefinitive Spec/std DataXD TYPE
Lifecycle & Compliance
Acquisition StatusCANCELLED
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
4730-00-189-2646INTERCHANGEABLE
UNION,PIPE

Frequently Asked Questions

What is NSN 4730-00-189-2645?

NSN 4730-00-189-2645 is a Union,pipe, manufactured by The American Society of Mechanical Engineers, classified under FSC 4730 (No Item Name Available). Status: cancelled.

What are the part numbers for NSN 4730-00-189-2645?

NSN 4730-00-189-2645 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 4730-00-189-2645?

There are 12 known substitutes for 4730-00-189-2645: 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: Operating Pressure: 300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS; Style Designator: SCREWED; Nondefinitive Spec/std Data: XD TYPE; Operating Pressure: 300.0 POUNDS PER SQUARE INCH (PSI) MAXIMUM SINGLE RESPONSE LBS. 25 total characteristics are documented in the Federal Logistics Information System.

Is NSN 4730-00-189-2645 still in active supply?

NSN 4730-00-189-2645 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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