This procurement specification covers alloy steel and corrosion and heat resistant steel free running metric nuts of the following types@ styles and classes. a. Types:Hex nut plain@ standard height Hex nut plain@ shear height Hex nut slotted@ standard height Hex nut slotted@ shear height b. Styles:Washer face Double chamfered Castellated c. Classes: 516 MPa axial strength@ min (shear height nuts) 600 MPa axial strength@ min (shear height nuts) 860 MPa axial strength@ min 1000 MPa axial strength@ min