ISO 7805-2:1987

Overview

ISO 7805-2:1987 establishes international guidelines for industrial plate screens with a thickness below 3 mm. Developed by the International Organization for Standardization (ISO), this standard focuses on perforated plates used in industrial sieving and screening applications, specifying three perforation patterns: round (circular) and square holes, with sizes ranging down to 2 mm (square) and 0.5 mm (round). Five pitch-to-hole ratios are provided, corresponding to nominal open areas from about 60% down to 23%. By standardizing dimensions, tolerances, and arrangements, ISO 7805-2 helps manufacturers, suppliers, and users achieve consistency and quality in plate screen production and application.

Keywords: ISO 7805-2, industrial plate screens, perforated plate, sieving, standard, open area, hole size, pitch, tolerances

Key Topics

• Hole Patterns and Shapes

  • Specifies three primary patterns: round holes (60° staggered), in-line square holes, and half-pitch staggered square holes.
  • Hole sizes: round holes down to 0.5 mm; square holes down to 2 mm.

• Pitch-to-Hole Ratios

  • Standardizes five pitch/hole ratios, resulting in approximate open areas from 60% to 23%.
  • Ratios ensure efficient material flow while maintaining plate integrity.

• Dimensional Standards and Tolerances

  • Provides detailed tolerances for average and individual hole sizes and pitches.
  • Ensures uniformity and performance of plate screens during industrial operations.

• Material and Design Requirements

  • Materials for plates under 3 mm thick should be agreed between manufacturer and purchaser.
  • Plate thickness must be less than both the hole size and the bridge (bar) width.

• Designation and Ordering

  • Designation includes hole shape, size, arrangement, orientation, and pitch.
  • Ordering must specify plate thickness, shape, size, and material requirements per ISO 7806 codification.

Applications

ISO 7805-2:1987 is essential for industries and sectors utilizing thin perforated plate screens for material sizing, segregation, and filtering. Typical applications include:

• Mineral processing and mining: For sizing aggregates and classification.
• Agriculture: Grain sorting and cleaning machinery.
• Food processing: Sifting, grading, or filtering solid ingredients.
• Pharmaceutical and chemical industries: Granular material handling and separation.
• Industrial manufacturing: Quality control and inline process screening.

By adhering to ISO 7805-2, organizations benefit from:

• Consistent screen performance and longevity
• Interchangeable components from different suppliers
• Improved product quality and process efficiency
• Compliance with international engineering and trade standards

Related Standards

ISO 7805-2 is part of a comprehensive suite governing industrial sieves and screens:

• ISO 7805-1: Industrial plate screens - Part 1: Thickness of 3 mm and above
• ISO 2194: Nominal sizes of apertures for wire and plate screens used in industry
• ISO 2395: Vocabulary for test sieves and sieving
• ISO 7806: Codification for designating perforations in industrial plate screens

These related standards address broader plate thicknesses, consistent nomenclature, and unified sizing methods. Implementing ISO 7805-2 alongside these standards ensures optimized screening processes and reliable, documented results across global industrial operations.