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
B28D5/021—Fine working of gems, jewels, crystals, e.g. of semiconductor material; apparatus or devices therefor by rotary tools, e.g. drills by drilling
B—PERFORMING OPERATIONS; TRANSPORTING
B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
Procédé de sectionnement ou de décalottage d'une partie tubulaire fermée notamment d'une pièce hydroformée et moyens destinés à le mettre en oeuvre