We manufacture and distribute Cast Iron Frames & Grates for several key markets in the U.S. Unless otherwise specified, round Rings & Grates have machined seated surfaces for a close, quite fit. Square or Rectangle Frames & Grates are furnished with ground seating surfaces. Options include bolt down grates and grates meeting ADA or High Heel requirements. Traffic rated Rings & Grates meet either AASHTO M306 H20 standards, where specified. Cast Iron meets ASTM A48 Class 30B or 35B, depending upon specifications.