When a diamond graver is manufactured, the diamond is ground and lapped to a conical point. During the engraving operation, the point of the tool penetrates the surface of the material and slices cleanly through it as the character is formed. A graver that is in good condition will produce a crisp, brilliant cut using moderate spindle pressure. Through use, the point of the diamond becomes rounded. When this occurs, it does not penetrate the material as easily or as deeply and tends to tear through the metal which results in a rough and less brilliant cut. As the condition worsens, it will require greater spindle pressure and multiple passes to achieve acceptable results. On color coated materials, a dull diamond can cause to coating to be smeared into the cut creating an uneven, blotchy appearance. On clear coated materials, the visual effect may not be as obvious, but it can adversely effect oxidizing. Since oxidizer solutions will only work on clean bare metal, those areas containing residue from the coating will not blacken and, once again, the appearance will be uneven and patchy. |
