Gilson ASTM 12" diameter round stainless steel test sieves meet the requirements of ASTM E 11. stainless steel frame with stainless steel cloth assures a sieve with the longest possible service life. This is the best choice where contamination, sanitation or extreme wear is an issue. Full-height, intermediate-height, or half-height frames available. All are serial numbered and supplied with a certificate of manufacturing conformance. Mesh opening sizes are listed using standard millimeter (mm) or micrometer (µm) descriptions, as well as traditional inch and number designations where appropriate. Gilson offers all mesh sizes, but not all sizes are available in every frame diameter. Common coarse sizes are also listed. Normally, every second or fourth size is used, although precision testing may require consecutive sizes. Additional sieves are often inserted into the sequence to avoid overloading of individual sieves or to better define a particular size range. Frame diameter should be large enough to accommodate the entire sample volume with enough surface area to avoid overloading individual sieves. The frame diameter selected must also fit the sieve shaker being used. Half or intermediate-height frames allow a greater number of sieves to be used when stack height is limited. Full-height frames allow free movement of larger particles during agitation for more efficient separation.