What material are ACO gullies made from? October 15, 2019 10:19 Updated ACO stainless steel gullies are manufactured from grades 304 and 316 stainless steel and are fully pickle passivated. To view full product details please visit www.aco.co.uk Related articles What size pipe do they fit? Where Can Threshold Drain Be Installed? Can I use Modular 125+ around a swimming pool or spa? Can you calculate the flow rate for my roof and tell me what size outlets I should use? Do they come in different sizes? Comments 0 comments Please sign in to leave a comment.