Forgings manufactured to this specification are intended for use in the fabrication of offshore structures@ marine risers@ TLP tendons and pipelines@ or other system components intended for application permanent offshore structures. This specification defines the minimum requirements for manufacture@ testing@ and inspection of carbon and low-alloy steel forgings@ including extrusions and heavy-wall seamless tubular product@ grades 345 N/mm2 to 586 N/mm2 (50 ksi to 85 ksi) for use in primary steel applications. Service categories A@ B@ and C (SCA@ SCB@ and SCC) reflect forging geometry and method of incorporation into the overall system@ rather than levels of criticality. They may also be designated by the user (purchaser) as described in 4.4 to reflect moderately different but standardized levels of performance.