(1) rough throwing
After milling, EDM, grinding and other processes can choose the speed of 35 000-40 000 rpm in the rotating surface polishing machine or ultrasonic grinding machine for polishing. Commonly used methods have the use of diameter Φ3mm, WA # 400 wheels to remove the white spark layer. Followed by hand-oil-stone grinding, strip of lime plus kerosene as a lubricant or coolant. The general use order is # 180 ~ # 240 ~ # 320 ~ # 400 ~ # 600 ~ # 800 ~ # 1000. Many mold manufacturers in order to save time and choose from # 400.
(2) semi-fine throwing
Semi-fine polishing mainly uses sandpaper and kerosene. The number of sandpaper is: # 400 ~ # 600 ~ # 800 ~ # 1000 ~ # 1200 ~ # 1500. In fact # 1500 sandpaper only for hardened die steel (52HRC above), not suitable for pre-hard Steel, as this may cause premixed steel surface burns.
(3) fine throwing
The main use of diamond polishing paste. The grinding order is usually 9 μm (# 1800) to 6 μm (# 3000) to 3 μm (# 8000) if the polishing is carried out using a polished cloth round diamond or abrasive paste. 9μm diamond grinding paste and polishing cloth wheel can be used to remove the # 1200 and # 1500 sandpaper leaving the hair wear marks. Followed by polishing with a felt and a diamond abrasive paste in the order of 1 μm (# 14000) to 1/2 μm (# 60000) to 1/4 μm (# 100000).