| 摘要 |
PURPOSE:To enable mass production and to obtain products having consistency in the stage of cutting a side-walled and long-sized blank material and producing metallic knobs for an acoustic device by providing a step to the side wall of the blank material and cutting the end part of the side wall left in the stage of slitting the blank material at the slightly larger width after working of knobs. CONSTITUTION:A step 3 is formed along the root of the side wall 2 of a blank material 1. A slit 4 is formed at every size of a desired knob to the material 1. The slit 4 is formed in the state of leaving the end part 5 of the side wall on the step side without including the step 3. The material 1 is then subjected to knob fabrication such as hairline working, alumite finishing, finishing of the slit surface or the like over the entire part and thereafter the end part 5 is cut slightly larger than the width of the slit 4. One metallic knob is completed by such cutting. Since the end part 5 is cut slightly larger than the width of the slit 4, burrs are formed on the inside without projecting to the slit 4. |
