Spool

Workpieces with a total length of 200 mm are precisely managed an accuracy of outer diameter dimension 3μ or less, circularity 2μ or less, and cylindricity 3μ or less. In addition, it is a product having extremely the high hardness that requires abrasion resistance, and the grinding after hard chrome plating manufactures with the required accuracy of the outer diameter dimension 2μ or less.