scope:

This specification covers steel derricks, steel substructures, and standard rigs. It includes stipulations on materials, design features, loadings, and allowable stresses. Recommended practices on the erection, care, and use of steel derricks are included as an appendix.

Nothing contained in this specification is to be construed as granting any right by implication or otherwise, for 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. This specification is for the convenience of purchasers and manufacturers in ordering and producing derricks. It is not intended to inhibit purchasers and producers from . purchasing and producing derricks meeting specifications other than those contained herein; nor is it intended in any way to inhibit purchasers from purchasing derricks from companies not authorized to use the API monogram.