| 摘要 |
<p>A hardened steel ball is pressed on to a metal surface while the two are moved relative to each other in several directions. For a cylindrical object, the ball is moved parallel to its axis at a steady rate and also reciprocated along the same axis while the cylinder turns. For impressing the end of the cylinder, a similar movement at right angles to the axis of the piece would be made. Surfaces so prepared ensures better sealing when used with rubber seals.</p> |
