聚甲醛塑料，俗称赛钢，为结晶性热可塑性塑料，具明显熔点165~175℃，性质Zui接近金属。
优点 1、具高机械强度和刚性
2、Zui高的疲劳强度
3、环境抵抗性、耐有机溶剂性佳
4、耐反覆冲击性强
5、广泛的使用温度范围(-40℃~120℃)
6、良好的电气性质
7、复原性良好
8、具自已润滑性、耐磨性良好
9、尺寸安定性优
缺点 1、加工过程若长时间高温下易起热分解
2、无自熄性
3、抗酸性差
4、成形收缩率大
用途 电子电器：洗衣机、果汁机零件、定时器组件
汽 车： 车把零件、电动窗零件
工业零件：机械零件、齿轮、把手、玩具、螺杆
Standing at the door with him were two of his three sons.The eldest83, baptized Santino but called Sonny by everyoneexcept his father, was looked at askance by the older Italian men;with admiration84 by the younger. Sonny Corleone was tallfor a first-generation American of Italian parentage, almost sixfeet, and his crop of bushy, curly hair made him look even taller.His face was that of a gross Cupid, the features even but thebow-shaped lips thickly sensual, the dimpled cleft85 chinin some curious way obscene. He was built as powerfully as a bulland it was common knowledge that he was so generously endowed bynature that his martyred wife feared the marriage bed asunbelievers once feared the rack. It was whispered that when as ayouth he had visited houses of ill fame, even the most hardened andfearless putain, after an awed87 inspection88 of hismassive organ, demanded double price.