吴淞砂产于上海附近的吴淞口,属于海砂的一种。粒度细而均匀,含坭量较少。从外形观察颗粒呈圆形,色泽灰暗。一般说来,它是适用于中小型的铸件。但因涨潮与落潮的缘故,砂内的含坭量相差甚大;必须分批严格测定,从而予以适当的控制。 Wusong sand production in Shanghai near the Wusongkou, a kind of sea sand. Smaller and more uniform size, with less content. From the shape of the particles were observed round, dark gray color. In general, it is suitable for small and medium sized castings. However, due to high tide and low tide reasons, there is a big difference between the content of sand; must be strictly determined in batches, so as to be properly controlled.