Overview
ISO 1050:1975 is an international standard published by the International Organization for Standardization (ISO) that specifies recommended values for the main dimensions of screw conveyors used in continuous mechanical handling of loose bulk materials. This standard provides standardized dimensions for key elements of screw conveyors including the helical screw, shaft, and trough to ensure compatibility, efficiency, and safety in bulk material handling applications.
Developed by ISO Technical Committee ISO/TC 101, this standard replaces the earlier ISO Recommendation R 1050-1969 and remains the authoritative guideline for manufacturers and engineers designing or selecting screw conveyors.
Key Topics
-
Helical Screw Dimensions
The standard defines nominal diameters and pitches for helical screws, specifying preferred sizes based on R10 and R20 series of preferred numbers. For example, nominal diameters range from 100 mm up to 1250 mm, while pitch sizes vary accordingly, supporting design flexibility for different bulk materials.
-
Shaft Construction and Dimensions
It outlines dimension recommendations for solid and tubular shafts with standardized diameters. Shaft ends must comply with ISO/R 775 to ensure proper interfacing with drive mechanisms. Shaft height and configuration affect conveyor robustness and material flow characteristics.
-
Trough Specifications
The trough’s key dimensions include shaft height, height above shaft, and radial clearance. Shaft height follows ISO 496 for driving and driven machines. Height above shaft relates directly to the screw’s nominal diameter, ensuring enough volume for material conveyance, while clearance is determined by material characteristics and operational conditions.
-
Preferred Number Series
The standard uses ISO 3 preferred numbers, ensuring consistent dimension selections that facilitate manufacturing ease, interoperability, and inventory management.
Applications
ISO 1050:1975 is essential for industries involved in bulk material handling such as:
-
Mining and Minerals Processing
Handling and transport of ores, sands, and aggregates efficiently within processing plants.
-
Agriculture and Food Processing
Conveying grains, seeds, and other loose agricultural products safely and hygienically.
-
Chemical and Pharmaceutical Manufacturing
Transporting powders and granulates with precise control over flow to prevent contamination or degradation.
-
Construction and Cement Production
Moving loose materials like cement, fly ash, and other bulk inputs accurately through production lines.
This standard helps manufacturers produce screw conveyors with consistent quality and dimensions, reducing design errors and simplifying maintenance or part replacement.
Related Standards
- ISO 496 – Specifies shaft heights for driving and driven machines, relevant for conveyor shaft positioning.
- ISO/R 775 – Defines cylindrical and conical shaft end dimensions to ensure proper drive component integration.
- ISO 3 – Covers preferred number series used for standardized dimension selection in mechanical design.
By adopting ISO 1050:1975, companies align with globally recognized engineering practices, facilitating international trade and equipment interoperability while optimizing conveyor system performance.
Keywords: ISO 1050, screw conveyor dimensions, bulk material handling, continuous mechanical handling equipment, helical screw size, conveyor shaft standards, trough clearance, conveyor design, ISO conveyor standards.
Open preview (PDF)Continuous mechanical handling equipment for loose bulk materials — Screw conveyors
