很多人在抛光时都会问说，我现在的表面应该是要过砂纸，还是要拿几番的金刚石膏磨料来处理，然后要搭配牛皮还是羊毛轮，一直以来在抛光界一直是个没订准的模糊地带，常常只能依靠老师傅的经验然后给出建议，再加以测试，如果试对了算运气好，试错了就再接再厉再来一次，正因为如此，我们认为在这问题上更需要一个明确的值，所以在这里问题上作出科学的定义与解释选用，
| 目数/颗粒大小um | Ra /um |
| #120/100um | 0.8~1.0 |
| #200/55um | 0.4~0.5 |
| #400/45um | 0.15~0.3 |
| #600/35um | 0.1~0.2 |
| #800/25um | 0.05~0.08 |
| #1000/17.5um | 0.045~0.06 |
| #1200/15um | 0.04~0.055 |
| #1500/13um | 0.035~0.045 |
| #1800/9um | 0.03~0.04 |
| #2000/8um | 0.025~0.03 |
| #3000/6um | 0.02~0.025 |
| #5000/4.5um | 0.018~0.023 |
| #8000/3um | 0.015~0.018 |
| #14000/1um | 0.009~0.013 |
| #28000/0.5um | 0.004~0.008 |
| #60000/0.25um | 0.002~0.003 |
| #150000/0.1um | 0.0015~0.002 |
| #300000/0.05um | 0.001~0.0013 |
| #500000/0.03um | 0.0007~0.001 |
| #1500000/0.01um | <0.0006 |
| #5000000/0.003um | <0.0003 |
