Sherardizing is the Thermal diffusion of Zinc at approx. 400 deg C into the surface of metal substrates , forming a Zinc Iron alloy ( the hardest of all Zinc applied coatings) the methodology of applying Sherardizing creates a very uniform coating on metal components following the component shape.
Sheraplex is a duplex coating ( two coating systems combined) Sherardizing and an organics sealent coating applied by either dip spin technology or spraying .This duplex coating is trademarked to Bodycote. The water industry in the U K specify Sheraplex for fasteners , to achieve 1000 hrs salt spray but also to meet the requirements of the Water Industry Specification W I S 4-52-03.
To produce protective coatings to this standard the coating systems have to meet all the requirements including Salt Spray 1000 hrs , damage resistance test, Torque tension testing . Sheraplex is accepted as a coating which meets all the requirements.