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
The mimicry of the Don was so extraordinary, sounexpected, that Hagen and Johnny were startled into laughter. DonCorleone was pleased. For a moment he reflected on how much heloved this godson. How would his own three sons have reacted tosuch a tongue-lashing? Santino would have sulked and behaved badlyfor weeks afterward244. Fredo would have been cowed. Michaelwould have given him a cold smile and gone out of the house, not tobe seen for months. But Johnny, ah, what a fine chap he was,smiling now, gathering245 strength, knowing already thetrue purpose of his Godfather.