| 摘要 |
PURPOSE:To engrave a colored blow mark of the same shape as a cut out hole by sand blasting the outer face of a cylinder masked leaving a cut out hole of desired shape with colored sand. CONSTITUTION:A cylinder (a) is transferred to a marking position A with the front of circular arc of the cylinder body on which marking is to be made kept in front. The cylinder (a) is masked with a mask 1 that has a cut-out hole 6 of desired shape. Then, colored sand (x) which is a mixture of blasting particles such as aluminum shot, scale shot, glass beads or sand grains is blasted on the cut-out hole. Thus, percussion dents of the same shape with the cut-out hole 6 are given, and at the same time, colored paint adheres to form a colored blow mark. |
