1.1 This specification covers carbon steel castings for general applications that require up to 70 ksi (485 MPa) minimum tensile strength. Note 1—The grades covered by this specification This specification covers carbon steel castings for general applications. The grades of steels covered here are: Grade N-1, Grade N-2, Grade U-60-30 [415-205], Grade 60-30 [415-205], Grade 65-35 [450-240], Grade 70-36 [485-250] and Grade 70-40 [485-275