Hygrade Products Limited 667B Great South Road , Penrose , Auckland 1061 New Zealand About Solutions products Companies Hygrade Products Limited Products Cast Iron Cast Iron 0 Share Nation wide coverage of all streetware requirements. Manhole covers, stormwater grates, surface boxes, including “S Mark” products. Most popular related searches manhole cover stormwater manhole stormwater manhole stormwater product manhole product Customer reviews No reviews were found for Cast Iron. Be the first to review! Add your review Publish your review Great! review successfully added!