Drawing Out & Spreading
开坯与延伸
标签：开坯, 延伸, 展宽, 锤打
开坯是把厚料锤薄拉长。延伸（拔长）：将坯料垂直轴线放置，锤击使其变细变长，每锤错开 90° 翻转以保证截面均匀。展宽：平放锤击使横向展开。要领：锤迹由中心向边缘、由厚向薄，保持厚度过渡平滑；随时回炉保温。铜的延伸率好，可拉成细长棒或薄片。
Drawing out thins and lengthens stock. To draw: orient stock perpendicular to the axis, hammer to thin and lengthen, rotating 90° each blow for even section. Spreading: hammer flat to widen. Rule: strikes from center to edge, thick to thin, smooth transitions; return to heat often. Copper's high ductility lets you draw long rods or thin sheet. ---