ASTM A453 Specification describes detailed requirements of grade 660 in class A,B,C & D (Edition 2020 Pdf).
ASTM A453 Grade 660 - https://astma453grade660.com,
ASTM A453 Grade 660 Class A Specification - https://astma453grade660.com/class-a-specification,
ASTM A453 Grade 660 Class B Specification - https://astma453grade660.com/class-b-specification,
ASTM A453 Grade 660 Class C Specification - https://astma453grade660.com/class-c-specification,
ASTM A453 Grade 660 Class D Specification - https://astma453grade660.com/class-d-specification,
ASTM A453 Pdf's - https://astma453grade660.com/astm-a453-pdf,
ASTM A453 Grade 660 Fasteners - https://astma453grade660.com/fasteners,
ASTM A453 Grade 660 Washers - https://astma453grade660.com/washers-plain-spring-belleville,
ASTM A453 Grade 660 Stud Bolts - https://astma453grade660.com/stud-bolts.