PartsTable TECHNICAL DATA SHEET
JULY 2026Technical Data Sheet

MIL-DTL-18866Elbow,pipe to Tube

Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M · NSN 4730-01-494-2257 · FSC 4730 · No Item Name Available
Verified by PartsTable
NSN 4730-01-494-2257 — this item is cataloged by the U.S. Government under National Stock Number 4730-01-494-2257. Primary manufacturer part number: MIL-DTL-18866.
Features
  • Elbow,pipe to Tube — FSC 4730
  • Thread Tolerance Class: 2A EXTERNAL FIRST END A
  • Flow Angle: 45.0 DEGREES
  • Surface Treatment: ZINC OVERALL
  • Connection Type: THREADED EXTERNAL TUBE FIRST END
  • Nominal Thread Size: 0.750 INCHES FIRST END IN
  • Nominal Outside Diameter Tube Accommodated: 0.500 INCHES ALL ENDS IN
  • Connection Type: THREADED EXTERNAL PIPE SECOND END
Applications
  • Fluid conveyance
  • Hydraulic system plumbing
  • Pneumatic line routing
  • Applications requiring Steel Overall construction
General Description

The Elbow,pipe to Tube, cataloged under National Stock Number 4730-01-494-2257, 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 17 verified specifications, sourced from the Federal Logistics Information System (FLIS). This item has 3 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
NSN4730-01-494-2257
Primary Part NumberMIL-DTL-18866
Item NameElbow,pipe to Tube
FSC / FSG4730 / 47 — No Item Name Available
ManufacturerMilitary Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
StatusACTIVE
Thread Tolerance Class2A EXTERNAL FIRST END A
Flow Angle45.0 DEGREES
Surface TreatmentZINC OVERALL
Connection TypeTHREADED EXTERNAL TUBE FIRST END
Nominal Thread Size0.750 INCHES FIRST END IN
Nominal Outside Diameter Tube Accommodated0.500 INCHES ALL ENDS IN
Connection TypeTHREADED EXTERNAL PIPE SECOND END
Thread Series DesignatorUNF FIRST END
Nominal Thread Size0.250 INCHES SECOND END IN
Connection StyleSWIVEL, PLAIN (PIPE) SECOND END
Connection StyleSWIVEL, PLAIN (TUBE) FIRST END
Furnished Items and Quantity1 NUT WITH SLEEVE
MaterialSTEEL OVERALL
Thread Series DesignatorNPTF SECOND END
Thread Class2A FIRST END A
Leg Length0.950 INCHES MINIMUM AND 1.010 INCHES MAXIMUM SECOND END IN
Thread Quantity Per Inch16 FIRST END
Lifecycle & Compliance
Acquisition StatusACTIVE
HAZMATNo
Verified Substitutes 2
4730-00-995-1568 INTERCHANGEABLE
Elbow,pipe to Tube
4730-01-494-2255 INTERCHANGEABLE
Elbow,pipe to Tube
Cross-Reference Index
Part NumberManufacturer
MIL-DTL-18866 Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M
MS51508 Military Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M
MS51508B8-4Z Military Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M
Related Parts
4730-00-995-1568INTERCHANGEABLE
ELBOW,PIPE TO TUBE
4730-01-494-2255INTERCHANGEABLE
ELBOW,PIPE TO TUBE

Frequently Asked Questions

What is NSN 4730-01-494-2257?

NSN 4730-01-494-2257 is a Elbow,pipe to Tube, 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: active.

What are the part numbers for NSN 4730-01-494-2257?

NSN 4730-01-494-2257 has 3 cross-referenced part numbers: MIL-DTL-18866 (Military Specifications Promulgated by Military Departments/agencies Under Authority of Defense Standardization Manual 4120 3-M), MS51508 (Military Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M), MS51508B8-4Z (Military Standards Promulgated by Military Departments Under Authority of Defense Standardization Manual 4120 3-M).

What NSN replaces 4730-01-494-2257?

There are 2 known substitutes for 4730-01-494-2257: 4730-00-995-1568, 4730-01-494-2255. Verify interchangeability with system specifications before substitution.

What are the specifications of MIL-DTL-18866?

Key specifications for MIL-DTL-18866: Part Name Assigned by Controlling Agency: ELBOW, PIPE TO TUBE; Thread Tolerance Class: 2A EXTERNAL FIRST END A; Flow Angle: 45.0 DEGREES; Surface Treatment: ZINC OVERALL. 18 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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