Form: This specification covers a premium-quality@ high strength@ alloy steel in the form of bars@ forgings@ mechanical tubing@ flash welded rings@ and stock for forgins or flash welded rings. Application: Primarily for parts@ such as pressure vessles@ requiring through hardening@ without quenching@ to a minimum yield strength of 270@000 psi (1862 MPa) and where such parts may require welding during fabrication.