FOREWORD These specifications were prepared by the Special A. P. I. Committee on the Standardization of Specifications for Steel and Iron Pips for Oil Country Tubular Goods. The work was initiated under the auspiecs of the Mid-Continent Oil and Gas Association in 1921. It was decided in 1922 to enlarge the Committee to include al lthe oil producing districts@ under the sponsorship of the American Petroleum Institute@ in order that the specifications might be national in scope. The American Society for Testing Materials rendered valuable assistance in outlining the scope of the work and in preparing tentative specifications. The Tables on drill pipe were pared by the A. P. I. Committee on the Standardzation of Rotary Drilling Equipment. The tables on drill pipe were pared by the Special A. P. I. Committee on the Standardization of Pumping Equipment as Applied to the Production of Oil.