IS 5961:1970 is the Indian Standard (BIS) for cast iron gratings for drainage purposes. This standard specifies the requirements for materials, manufacture, dimensions, and testing of cast iron gratings intended for use in drainage systems. It classifies gratings into Light, Medium, and Heavy Duty based on their intended location and traffic load.
cast iron gratings for drainage purposes
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Primary Material | Grey Cast Iron conforming to IS 210 | Grey Cast Iron (EN-GJL) or Spheroidal Graphite (Ductile) Cast Iron (EN-GJS) | EN 124-2:2015 |
| Load Class (Road Carriageway) | Medium Duty (10 Tonnes) / Heavy Duty (20 Tonnes) | Class D400 (400 kN / approx. 40.8 Tonnes test load) | EN 124-1:2015 |
| Load Class (Pedestrian Area) | Light Duty (5 Tonnes) | Class B125 (125 kN / approx. 12.7 Tonnes test load) | EN 124-1:2015 |
| Proof Load Test Duration | 30 seconds | Load applied progressively then held for 30 ± 2 seconds | EN 124-1:2015 |
| Maximum Permanent Set (Deformation) | 1.5 mm for Heavy Duty grating of 455 mm size | Permissible set is a fraction of the clear opening, e.g., Clear Opening (mm) / 500. | AS 3996:2019 |
| Skid Resistance Requirement | Not specified | Required for units in pedestrian or traffic areas; specific test methods and minimum values are defined. | EN 124-1:2015 |
| Waterway Area | Implicit in dimensional drawings; not a formal requirement. | Must be calculated and declared by the manufacturer. | AS 3996:2019 |
| Load Application Block for Testing | A specific block size is defined for each grating type (e.g., 250 x 250 mm for Heavy Duty) | Test block shape (circular or rectangular) and size are defined by the load class (e.g., Ø250 mm for Class D400) | EN 124-1:2015 |