1.1 Scope:This specification covers helical compression and extension springs, made from single wire or rod ofeither round or special cross-section (see 6.4).1.2 Classification:The springs shall be of the following types and grades (see 6.2).1.2.1 Types:Type I - CompressionType II - ExtensionGradesGrade A - Highly stressed or critical applications (recoil springs and other special applications)(see 6.1).Grade B - General applications (see 6.1).