18.50cm Grade 74 Medium Speed Ashless Filter Paper. Grade 74, 2.0µm - Medium Speed has medium flow rate and good particle retention and is the most commonly used acid-washed filter. Covers a wide range of general ashless filtration applications. It is used for gravimetric analysis of numerous components (e.g.: cements, copper, clay, bismuth, silicon, iron) found in heavy industries such as construction, mining or steel. Used as a high purity filter for speedy filtering of trace elements such as silver chromate, lead sulfate, zinc and ammonium hydroxides. Also found in general soil analysis for separating solid from aqueous extracts. Size: 18.50cm. 100/Pack. Ahlstrom #: 0740-1850.