Coverage. This recommended practice involves not only the selection of drill string members@ but also the considerations of hole angle control@ drilling fluids weight and rotary speed. and other operational procedures. Sections 2@ 3@ 4@ and 5 provide a step-by-step procedure for selection of drill string members in normal. near vertical holes. Sections 6@ 7. 8@ and 11 are related to operating limitations which may reduce the normal capability of the drill string. Section 9 contains classification system for used drill pipe and inspection procedures for other drill string members. Section 1 contains statements regarding welding on down hole tools. Policy. This API Recommended Practice ma)' be used by anyone desiring to do 80@ and every effort has been made by the Institute to assure the accuracy and reliability of the data contained. However@ the Institute make. no representation warranty@ or guarantee in connection with the publication of any API recommended practice 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 recommended practice may conflict. or for the infringement of any patent resulting from the use of an API recommended practice.