Indo Iron Foundry [P] Ltd. Manufactures Cast Iron Circular Manhole Cover. Indo Iron Foundry [P] Ltd. Is an ISI accredited company manufacturing a wide range of domestic fittings and pipes. The Cast Iron Circular Manhole Cover is available in various sizes with diameters of 370 mm, 450 mm, 480 mm and 500 mm. The Cast Iron Circular Manhole Cover is available in various specifications to suit both industrial and domestic applications as a sanitary fitting.