Cylindricity - Circular

…In contrast to these radial roundness methods, the diameter roundness method, which utilizes the characteristics of a circle and is expressed as the maximum difference in diameter in several directions in a cross section perpendicular to the axis of a cylinder or a circular hole, and the three-point roundness method, which is expressed as the range of variation in the height of the top surface of a cylinder when it is placed on a V-block and rotated as in Figure 2a, or the range of variation in the readings of a tripod gauge in a circular hole as in b, are used as simplified methods. Since it is not easy to determine the cylindricity of a cylindrical body, it is often estimated by the roundness, the straightness of the axis, and the parallelism of the opposing generating lines. [Masaji Sawabe] …

*Some of the terminology explanations that mention "cylindricity" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…これらの半径法真円度に対し，円のもつ特性を利用して，円柱や丸穴の軸線に直角な断面内の数方向の直径の最大差で表す直径法真円度，図2のaのように円柱をVブロックにのせて回したときの円柱上面の高さの変動の範囲や，bのように丸穴での三脚ゲージの読みのばらつきの範囲で表す三点法真円度が，簡便法として用いられている。　円筒形体の狂いである円筒度を求めることは容易ではないので，真円度，軸線の真直度，相対する母線の平行度で円筒形体を推定することが多い。【沢辺 雅二】。…

※「円筒度」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報