B28D5/00—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor
B28D5/02—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by rotary tools, e.g. drills
B28D5/022—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by rotary tools, e.g. drills by cutting with discs or wheels
B28D5/024—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by rotary tools, e.g. drills by cutting with discs or wheels with the stock carried by a movable support for feeding stock into engagement with the cutting blade, e.g. stock carried by a pivoted arm or a carriage
B28D5/025—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by rotary tools, e.g. drills by cutting with discs or wheels with the stock carried by a movable support for feeding stock into engagement with the cutting blade, e.g. stock carried by a pivoted arm or a carriage with the stock carried by a pivoted arm