Specifications include, but are not limited to: All cast iron castings shall conform to ASTM A48, Class 35B & AASHTO M105 Class 35B. or County approved equal. Castings shall conform to the requirements of AASHTO M306, Standard Specification for Drainage, Sewer, Utility, and Related Castings, and as such, shall be true to pattern in form and dimensions with component parts fitting together in a satisfactory manner. Dimensional tolerances shall not exceed ± 1/16th inch per foot and casting weights deviation shall not exceed ± 5%. All castings shall be free from pouring faults, sponginess, cracks, blowholes and other defects. Heavy duty round manhole frames, covers and grates shall be furnished with machined horizontal bearing surfaces. All other types of castings shall be furnished with a cast-bearing surface unless otherwise specified. ; Steel products shall fit component parts in a satisfactory manner. Steel shall conform to ASTM A36 (36KSI Yield strength) or ASTM A529 grade 50 (50KSI Yield strength) as required to achieve adequate design strength. All units intended for use in roadways shall be designed to resist the 20 KIP wheel load for HS-25. All fabricated products shall be galvanized after fabrication and shall conform to ASTM 123.