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
'And what about her hands?' said Dick. 'A farmer's wife does agreat deal of hard, rough work, andher hands are never white andsmooth - they are rough and brown. This woman's hands were aswhiteas a princess's!'
'Well yes - I did notice them,' said Anne. 'And I did notice toothat she sometimes spoke like acountry-woman and sometimesnot.'
'Well, there you are!' said Julian. 'She's one of the unpleasantgang that tried to scare us last night- and when the watcher on thehill reported that we appeared to be packing up and going, shewastold to go and make sure. So she pretended to be a country womanand came by - but unfortunatelywe weren't quite so stupid as shethought we would be!'
'You certainly stuffed her up well!' said Dick, with a grin. 'Thegang will be down here tonight,digging up all the big stones theycan find. You and I will have a marvellous time, snoopingroundthem.'