ASME B5.18

Abstract

The first edition of this standard, known as B5.18-1943, resulted from intensive efforts dating back to 1926 by a special group of milling machine manufacturers; it was reaffirmed in 1949, revised in 1953 and again in 1960. ASA B5.18-1960 incorporated several changes and corrections. It also included a new spindle nose size, designated as 50 A, suggested by the 'Society of Manufacturing Engineers' and several recommendations made by a special committee of fifteen milling machine manufacturers appointed by the National Tool Builder's Association. The revised standard reflected accurately the actual practice at this period of time. <br> This revision is based on the recommendations of the Technical Committee No. 33 of the American National Standards Committee B5 for 'Standardization of Machine Tools, Components, Elements, Performance, and Equipment'. It updates the 1960 standards; incorporates several recommendations made by members of industry as users and by machine tool builders; it follows the Decimal Inch practice according to ASA B87.1-1965, Several notes have been added, tolerances more clearly defined and conformity with pertinent American National Standards obtained. <br> The true position dimensions and symbols contained herein are based on American National Standard Y14.5-1966 "Dimensioning and Tolerancing for Engineering Drawings." <br> Upon the suggestion of the International Organization for Standardization (ISO) a No. 45 size number of spindle nose and tool shank has been added to meet a need for an intermediate size between the 40 and 50 size numbers. <br> The draft of the proposed revision was submitted to the Technical Committee No. 33 for final review and comments. <br> The final draft of the proposed revision was processed according to the established procedures of ANSI; it was voted on by letter ballot, approved by the American National Standards Institute on August 22, 1972 as ANSI B5.18-1972.