ISO 1179-4:2007

Overview

ISO 1179-4:2007 specifies dimensions, performance requirements and test procedures for stud ends with ISO 228-1 threads and metal-to-metal sealing intended for general use (type B). The standard applies to stud ends used with ports and connectors in fluid conveyance systems but explicitly states these stud ends should not be used for leak‑free hydraulic fluid power applications. Stud ends conforming to ISO 1179-4 are intended for use up to defined working pressures depending on series (S, L, LL) and require manufacturer testing to verify rated performance.

Key topics and technical requirements

• Threading and sealing: Uses ISO 228-1 pipe threads; sealing is metal‑to‑metal (no elastomeric O‑ring).
• Dimensions and tolerances: Detailed geometries and hexagon tolerances (ISO 4759‑1 product grade C) are provided (Figure/Table references in the standard).
• Working pressures by series: Typical permissible working pressures (for low carbon steel parts) are:
  • S series: up to 40 MPa (400 bar)
  • L series: up to 25 MPa (250 bar)
  • LL series: up to 10 MPa (100 bar)
• Performance tests:
  • Burst (failure) test: three samples, with a required burst-to-working pressure ratio of 4:1.
  • Cyclic endurance (impulse) test: six samples must survive 1,000,000 cycles at the specified impulse pressure.
  • Test blocks and procedures reference ISO 19879 (materials, pressure rise rate, lubrication).
• Material and finishing: Typical test materials are low carbon steel with plating; manufacturers must certify hardness and tensile values in test reports.
• Assembly considerations: Metal-to-metal sealing deforms the port sealing face-safe reassembly is not possible. Test torques are specified (Table 3) for qualification; note: these torques are for testing only-actual assembly torque depends on lubrication, coating and surface finish.
• Designation and identification: Stud ends are designated with the part reference (ISO 1179-4), thread size and series (e.g., “Stud end ISO 1179-4 - G 3/8 A-S”).

Applications and who uses it

ISO 1179-4 is relevant to:

• Hydraulic and pneumatic component manufacturers producing threaded stud ends and connectors for general use
• Test laboratories performing burst and impulse qualification
• Design engineers and procurement teams specifying threaded connections for piping, hose fittings, and tube assemblies where metal-to-metal sealing is acceptable
• Maintenance and quality assurance personnel validating connector performance and traceability

This standard is particularly useful when ISO 228-1 threaded stud ends with metal sealing are required and when users need a clear testing and designation framework.

Related standards

• ISO 1179 parts 1–3 (ports and other stud end types)
• ISO 228-1 (pipe thread dimensions)
• ISO 19879 (test methods for metallic tube connections)
• ISO 6149, ISO 8434 series (related hydraulic/connector standards)

Keywords: ISO 1179-4:2007, stud ends, ISO 228-1, metal-to-metal sealing, fluid power, working pressure, burst test, impulse test, connector standards.