Overview
EN ISO 9974-2:2000 (ISO 9974-2:1996) covers stud ends with elastomeric sealing (type E) used for ports and stud-end connections with ISO 261 metric threads in general-use and fluid-power applications. The standard specifies dimensions, designation, performance requirements and test procedures for light‑duty (L series) and heavy‑duty (S series) stud ends and their elastomeric seals. It also defines test seal material/hardness and the format for product identification.
Key topics and technical requirements
- Scope: Dimensions and performance for L and S series stud ends with ISO 261 threads and elastomeric seals; designation rules for stud ends and seals.
- Rated pressures: S‑series may be used up to about 63 MPa (630 bar) and L‑series up to 25 MPa (250 bar) (actual permissible pressure depends on size, material and application).
- Mechanical tests:
- Burst test: Three samples; standard requires a minimum burst-to-working pressure ratio (tested under controlled pressure rise).
- Cyclic endurance (impulse) test: Six samples; requirement typically 1,000,000 cycles at specified impulse pressure.
- Test materials and conditions:
- Test seals: Nitrile (NBR) with hardness 90 ± 5 IRHD.
- Test blocks: unplated, hardened to 50–55 HRC.
- Thread lubrication for testing with hydraulic oil VG 32.
- Assembly/qualification torques: Standard provides test torque values (for qualification only); actual assembly torque depends on lubrication, coating and finish - consult manufacturer.
- Designation examples:
- Stud end: “Stud end ISO 9974-2 – M12×1.5 S”
- Elastomeric seal: “Elastomeric seal ISO 9974-2 – M12×1.5”
- Important note: Conformance to dimensional data alone does not guarantee performance; manufacturers should perform the specified tests to verify ratings. For new hydraulic fluid‑power designs ISO 6149 is preferred.
Applications and users
- Typical users:
- Hydraulic and pneumatic system designers and engineers
- Fittings, hose and tube manufacturers
- Quality and test laboratories performing burst/impulse qualification
- Procurement and specification authors drafting component requirements
- Practical applications:
- Specifying and qualifying threaded stud ends on hose fittings, tube fittings and ports where ISO 261 threads and elastomeric seals are used
- Ensuring compatibility of seals and thread dimensions for maintenance, replacement and interoperability
- Verifying product safety and endurance for high‑pressure fluid systems
Related standards
Keywords: EN ISO 9974-2:2000, ISO 9974-2, stud ends, elastomeric sealing, ISO 261 threads, fluid power, burst test, impulse test, S series, L series.
