Tolerance on outer diameter and wall thickness should be observed,but for the following two circum stances,shorter axis should not be less than 95% of nominal diameter.

• 管材的不圆和壁厚不匀，应不超出外径的壁厚允许偏差，但属下列两种情况之一者，其短轴尺寸应不小于公称外径的95%25。