表面粗糙度 规格表
2种规格数据
表面粗糙度以Ra、Rz等数值表示加工面的微观凹凸程度。密封面通常要求Ra 0.4以下，一般加工面Ra 6.3以下。在图纸上正确标注粗糙度可兼顾加工成本和功能质量。
常见问题 (FAQ)
What is the difference between Ra and Rz surface roughness?
Ra (arithmetic mean roughness) is the average height variation over a measured section. Rz (maximum height) is the difference between the highest peak and deepest valley. Ra reflects overall roughness; Rz reflects extremes. Generally Rz ≈ 4×Ra.
How do I choose surface roughness values?
Sealing and bearing contact surfaces: Ra ≤0.8; general fit surfaces: Ra 1.6–3.2; unmachined/structural surfaces: Ra 6.3–12.5. Finer roughness increases machining cost.