... Detailed Product Description sifterTest sieve screen surface material according to wire ... : 1990 R20 / 3, R20, R40 / 3 series, the screen made of brass, tin bronze, stainless steel. Perforated ... 1990 R20 / 3, R20, R40 / 3 series, the screen made of copper, and made use of electrochemical machining ... . Test sieve box, screen cover, screen at the end of selection of high-quality ...