Coverage. This specification covers intermediate strength steel plates up to 3 in. thick for use in welded tubular construction of offshore platforms@ in selected critical portions which must resist impact@ plastic fatigue loading@ and lamellar tearing. This material is intended for fabrication primarily by cold forming and welding as per API Spec 2B. Welding procedure is of fundamental importance and it is presumed that procedures will be suitable for the steel and the intended service. Conversely@ the steel should be amenable to fabrication and welding under shipyard and offshore conditions. The primary use of this steel is in tubular joints where portions of the plates will be subject to tension in the thickness direction (Z direction). Supplementary Requirement S-4 provides for thru-thickness (Z direction) testing of the plates by the manufacturer and specifies limits for rejection. The presence of laminations and large non-metallic inclusions in these portions of the plates can be extremely damaging. Supplementary Requirement S-1 provides for ultrasonic inspection of the plates by the manufacturer and specifies limits for rejection. If Supplementary Requirement S-1 is not used@ it is recommended that the plates be subjected to ultrasonic inspection in the fabrication yard prior to being formed into tubular members. Areas of lamination can be determined and marked to permit the placing of these areas where they will not be subject to thru-thickness loadings. The notch toughness requirements specified in Section 6 are suitable for application below water or above water in areas of temperate climate ( UT minimum service temperature). Cold formed tubulars have less toughness due to straining than that of the original flat plate especially in those areas aged by the attachment welding of stubs or braces. The requirements for plates in Section 6 take typical losses in toughness due to straining and ageing into consideration. For areas with lower service temperatures. commensurately lower test temperatures shall be used. or fabrication process shall be modified to limit degradation. Supplementary Requirement S-2 provides for impact tests at temperatures other than specified in Sect. 6. Policy. American Petroleum Institute (API) specifications are published as an aid to procurement of standardized equipment and materials. These specifications are not intended to inhibit purchasers and producers from purchasing or producing products made to specifications other than API@ and nothing in any API specification is intended to in any way inhibit the purchase of products from companies not authorized to use the API monogram.* Nothing contained in any API specification is to be construed as granting any right@ by implication or otherwise@ for the manufacture@ sale@ or use in connection with any method@ apparatus or product covered by letters patent@ nor as insuring anyone against liability for infringement of letters patent. API specifications may be used by anyone desiring to do so@ and every effort has been made by the Institute to assure the accuracy and reliability of the data contained in them. However@ the Institute makes no representation@ warranty or guarantee in connection with the publication of any API specification and hereby expressly disclaims any liability or responsibility for loss or damage resulting from their use@ for any violation of any federal@ state or municipal regulation with which an API specification may conflict@ or for the infringement of any patent resulting from the use of an API specification. The use of the API monogram is a warranty by the manufacturer to the purchaser that the manufacturer has obtained a license to use the monogram and. further@ that the product which bears the monogram conforms to the applicable API specification. However. the American Petroleum Institute does not represent. warrant or guarantee that products bearing the API monogram do in fact conform to the applicable API standard or specification. *The API monogram ??AP-is a registered trademark of the American Petroleum Institute.