BS 6620-1:1991

Committees responsible
National foreword
Guide
0. Introduction
1. Scope and field of application
2. References
3. Definitions
4. Material and design
5. Tolerances
6. Testing
7. Designation
Annex
Examples
Tables
1. Pitch/hole ratios and related open areas
2. Examples of round hole perforations at 60 deg
    stagger in industrial plate screens
3. Examples of square hold perforations in industrial
    plate screens
4. Examples of tolerances on pitch
Figures
1. Round holes: 60 deg staggered arrangement
2. Square holes: in-line arrangement
3. Square holes: half-pitch staggered arrangement

Describes three patterns using round and square perforations in plate of 3 mm thickness and above.

This part of ISO 7805 describes three patterns using round (circular) and square perforations in low carbon steel plate of 3 mm thickness and above; the sizes of holes ranging from 125 to 3,15 mm inclusive. Five ratios of pitch to hole are prescribed which result in nominal areas ranging from about 64 to 23 %. Tolerances for both hole and pitch are given.

As this part of ISO 7805 provides a diversity of choice, it is unlikely that every one of the many possible combinations of size of hole, pitch and plate thickness will be manufactured. The selection for national standards for industrial plate screens should be made from those combinations which suit the products and screening methods in the country concerned.

Industrial plate screens of thicknesses below 3 mm are dealt with in ISO 7805-2.