摘要 |
<p>The present invention relates to a manufacturing method for an under-drive brake piston material as one of a power transmission means installed inside an automatic transmission and, more specifically, relates to a manufacturing method for an under-drive brake piston material for an automatic transmission contained in the power transmission means wherein the power transmission means is a circular disk frame shape which a through hole is formed inside, and moreover, is formed by a plurality of fixating pieces which protrude by leaving a space on a portion of an outer diameter.</p> |