| 摘要 |
<p>In the wall of the tin body grooves are introduced between tools radially movable in opposite senses towards the tin body, one tool being provided with ridges and the other with grooves registering with the ridges. This method makes it possible, contrary to the usual rollers, to introduce grooves with fairly small tolerances. Damage of the lacquer does not occur. Because of the forming of sharper grooves the radial strength will be improved and the wall thickness of the tin body can be reduced.</p> |
