manhole cover

AASHTO M 306-07

In 2007, the American Association of State Highway and Transportation Officials (AASHTO) developed specifications for frames, grates, rings, and covers.

  • You may wish to protect yourself and your jurisdictions from specification liability issues by implementing AASHTO M-306-07.
  • This specification is applicable to frames, grates, rings, and covers for inlets, manholes, and other structures for civil engineering use where tensile strength is a major consideration.
  • AASHTO M-306-07 was implemented in 2005 and requires that municipal castings conform to the requirements of “Gray Iron Castings” AASHTO M105-06/ASTM A48 Class 35B. It further calls for a 40,000 pound proof load for H-20 traffic and 50,000 pound proof load for H-25 traffic. These proof load values represent a 2.5 safety factor over H 20 (16,000 lb) and H 25 (20,000 lb) wheel loads. It is the most recent and most stringent specification dealing with these products. Contact MCA at for information on how to obtain a copy of AASHTO M-306-07.
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