ISO 6149-1:2022

Overview

ISO 6149-1:2022 specifies metric ports with truncated housings for O‑ring sealing used in hydraulic fluid power and general-purpose applications. The standard defines port dimensions, identification and designation conventions for ports that mate with ISO 261 metric-thread stud ends (see ISO 6149‑2 and ISO 6149‑3 for stud-end details). Ports conforming to ISO 6149‑1 are suitable for high‑pressure hydraulic systems, with permitted working pressures up to 63 MPa (630 bar) for non‑adjustable stud ends and 40 MPa (400 bar) for adjustable stud ends (actual permissible pressure depends on size, material and application).

Keywords: ISO 6149-1, metric ports, O-ring sealing, hydraulic fluid power, ISO 261, stud ends, port dimensions, hydraulic fittings

Key topics and technical requirements

• Port geometry and dimensions: Defines sizes and dimensional limits for metric ports (covers common thread sizes from M8 to M60 as listed in the standard) including spotface, tap depth and counterbore/raised‑boss requirements.
• Threading and tolerances: Uses ISO 261 metric threads and tolerance grade 6H in accordance with ISO 965‑1; tap drills per ISO 2306.
• O‑ring sealing arrangement: Ports are designed with a truncated housing to accept O‑ring seals for reliable fluid sealing.
• Working pressure guidance: Specifies maximum working pressures for use with matching stud ends; notes that allowable pressure depends on port size, material, component design and operating conditions.
• Identification and designation: Ports must be identified by a raised ring, a permanent “M” or “metric” marking, or a label referencing ISO 6149‑1:2022; required designation format is described.
• Testing and interchangeability: Calls out testing methods and requirements to be performed with stud ends per ISO 6149‑2 and ISO 6149‑3. Includes a clear interchangeability warning about hazards when mixing these ports with older port/stud systems (e.g., ISO 1179, ISO 9974, ISO 11926).

Applications and who uses this standard

• Hydraulic system designers and OEMs specifying ports for pumps, motors, valves and cylinders
• Component manufacturers (ports, manifold fabricators, valves, cartridge cavities)
• System integrators, maintenance and service engineers, and procurement specialists ensuring compatibility and safety
• Test laboratories and quality teams performing pressure and leak tests per ISO 6149 series

Benefits include improved interchangeability, predictable sealing performance with O‑rings, and alignment with modern metric thread practices for hydraulic fittings.

Related standards

• ISO 6149‑2 (stud ends - heavy‑duty S series)
• ISO 6149‑3 (stud ends - light‑duty L series)
• ISO 261 / ISO 965‑1 (metric threads and tolerances)
• ISO 2306 (tap drills)
• Referenced legacy families: ISO 1179, ISO 9974, ISO 11926 (caution advised when mixing systems)

For implementation, consult the full ISO 6149‑1:2022 document and related parts for detailed tables, figures and test procedures.