"Coverage. This specification covers Grade C-75 seamless steel casing and tubing@ in the sizes and wall thicknesses sho"" ... n in the standard lists (Tables 1.1 and 1.2)@ and the dimensional tables (Tables 6.1 through 6.6). It also includes requirements for couplings and thread protectors. Dimensional requirements on threads and thread gages@ stipulations on gaging practice@ gage specifications and certification@ as well as instruments and methods for inspection of threads are given in API Std 5B and are applicable to products covered by this specification. Although this specification@ in conjunction with API Std 5B@ permits manufacturers authorized to use the API monogram on round-thread casing to manufacture and apply the monogram to buttress and extreme-line casing@ considerable skill and know-how is required for the tooling for@ and machining of@ these joints. Therefore@ any manufacturer who desires to produce these joints is advised to consult with manufacturers who have produced these joints before attempting their manufacture. NOTE: This specification is tentative and the API monogram cannot be applied to pipe covered by this specification. 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 Petdoleum Institute."