Overview
ISO 3019-1:2001 - Hydraulic fluid power - Dimensions and identification code for mounting flanges and shaft ends of displacement pumps and motors - Part 1: Inch series shown in metric units specifies sizes, dimensional tolerances and an identification code for two- and four-bolt mounting flanges and shaft ends used on positive-displacement rotary hydraulic pumps and motors. The part covers cylindrical keyed shafts (with and without external thread), conical keyed shafts with external thread and 30° involute spline shaft ends (in accordance with SAE J744). It presents the inch-series geometry converted to metric units for clear international use.
Key topics and requirements
- Dimensional specifications for two-bolt and four-bolt mounting flanges and multiple shaft-end types, with illustrative figures and tables for nominal sizes (e.g., 50-2, 101-4 flange codes).
- Identification code system:
- For flanges: the number before the hyphen approximates the flange pilot diameter in millimetres; the number after the hyphen is the number of bolt holes.
- For shaft ends: the number before the hyphen approximates the shaft major diameter in millimetres; suffix codes indicate shaft type (‑1 cylindrical keyed without thread, ‑2 cylindrical keyed with external thread, ‑3 conical keyed with external thread, ‑4 30° involute spline).
- Tolerances and geometric control: dimensions without explicit tolerances are nominal; form and position tolerances align with ISO 1101. Required flange/shaft concentricity and perpendicularity are specified (see figures), and note that rigid couplings may require closer tolerances.
- Mating component compatibility: guidance to ensure mating parts respect the specified dimensions/tolerances to avoid undue body strain or excessive transverse shaft loads.
- Preferred flange/shaft combinations and guidance for alternative combinations by agreement between purchaser and supplier.
- Normative references include ISO 68-2 (inch screw threads), ISO 1101 (geometrical tolerancing), ISO 5598 (fluid power vocabulary) and SAE J744 for spline form. Annex A gives inch thread basic dimensions.
Applications and users
ISO 3019-1 is essential for:
- Hydraulic pump and motor manufacturers and design engineers for standardizing mounting interfaces.
- OEMs and machine builders specifying interchangeable pump/motor mounts and shaft connections.
- Maintenance, procurement and quality teams ensuring parts compatibility and correct replacement components.
- Coupling and transmission designers checking shaft/flange fit, concentricity and run-out requirements.
Using ISO 3019-1 reduces design rework, improves cross-brand interchangeability and simplifies procurement of hydraulic displacement pumps and motors.
Related standards
Open preview (PDF)Hydraulic fluid power — Dimensions and identification code for mounting flanges and shaft ends of displacement pumps and motors — Part 1: Inch series shown in metric units