United States Standard: AASHTO M 306 Standard Specification for Drainage, Sewer, Utility, and Related Castings, with a 40,000-pound proof load concentrated on a 9-inch-by-9-inch square area and held for one minute.
H-25 & HS-25: A 50,000-pound proof load concentrated on a 9-inch-by-2- inch square area and held for one minute.
STAHL CraneSystems has designed and built a unique test rig, where cranes up to a Safe Working Load (SWL) of 120 tons (
proof load of 150 tons) and a span of 25 m can be tested in the future.
The
proof load of 140 kN amounted to between 58% and 97% of the observed failure load.
Custom 465 stainless could actually withstand up to 92,000 psi so the 70,000 psi of Casull's
proof loads have a considerable margin of safety.