ISO 1179-3:2007

Overview

ISO 1179-3:2007 defines dimensional, performance and test requirements for light-duty (L series) stud ends with ISO 228-1 threads that use O‑ring sealing with a retaining ring (types G and H). It applies to non‑adjustable (type G) and adjustable (type H) stud ends used in general and fluid‑power applications (hydraulic and pneumatic). The standard covers geometry, sealing components, burst and cyclic endurance performance, test procedures and designation rules.

Key topics and technical requirements

• Scope & use: Stud ends for working pressures up to 31.5 MPa (315 bar) for non‑adjustable type G and up to 20 MPa (200 bar) for adjustable type H (actual permissible pressure depends on size, material and application).
• Dimensions: Detailed dimensions for stud ends, locknuts and washers are specified; hex tolerances follow ISO 4759‑1 (product grade C).
• Sealing components: O‑rings and retaining rings conform to the dimensions in the standard; O‑rings should meet or exceed grade N in ISO 3601‑3.
• Materials: Performance data in ISO 1179‑3 is based on stud ends made from low carbon steel (plated); manufacturers must validate performance for other materials.
• Performance tests:
  • Burst pressure test: Three samples required; burst-to-working pressure ratio of 4:1 is specified.
  • Cyclic endurance (impulse) test: Six samples, 1,000,000 cycles at the impulse pressure without leakage or component failure.
  • Thread lubrication, torque application and pressure rise rates are prescribed (refer to ISO 19879 for test block and procedure details).
• Designation & identification: Standardized naming (example: “Stud end ISO 1179-3 - G 3/8 A - G”) and recommended identification statements for catalogs and test reports.
• Manufacturer responsibility: Conformance to dimensions alone does not guarantee rated performance-manufacturers must perform the specified tests.

Applications and who uses this standard

• Used by designers, manufacturers and quality/test laboratories of hydraulic and pneumatic connectors and fittings.
• Relevant to component suppliers, OEMs, maintenance engineers and procurement teams working with legacy systems that use ISO 228‑1 threaded stud ends.
• Particularly applicable where compact, light‑duty stud ends with O‑ring sealing are required (tubes, hoses, shaped connectors such as tees and elbows interfacing with ISO 8434‑2 connectors).

Related standards

• ISO 228‑1 - pipe thread dimensions (non‑pressure‑tight on threads)
• ISO 3601‑3 - O‑ring quality acceptance
• ISO 19879 - test methods for hydraulic connections
• ISO 1179 (parts 1, 2, 4) - other ports and stud end types
• ISO 8434‑2 - connector details that interface with ISO 1179‑3

Keywords: ISO 1179-3:2007, light-duty stud ends, ISO 228-1 threads, O-ring sealing, retaining ring, fluid power, burst pressure, cyclic endurance, hydraulic connectors.