Hygrade Products Limited 667B Great South Road , Penrose , Auckland 1061 New Zealand About Solutions products Companies Hygrade Products Limited Products Ductile Iron Ductile Iron 0 Share The premier range of gas and air tight access covers in all load strengths. Most popular related searches Customer reviews No reviews were found for Ductile Iron. Be the first to review! Add your review Publish your review Great! review successfully added!