Flowability Chart

Class 1	ANGLE OF SURCHARGE: ANGLE OF REPOSE: FLOWABILITY:	5 degrees 0 - 20 degrees Very free flowing
	MATERIALS: Very small rounded particles, very wet or very dry, such as dry silica sand, cement, wet concrete, etc.
Class 2	ANGLE OF SURCHARGE: ANGLE OF REPOSE: FLOWABILITY:	10 degrees 20 - 30 degrees Free flowing
	MATERIALS: Rounded dry polished particles of medium density such as whole grain, beans, salt, sugar, etc.
Class 3	ANGLE OF SURCHARGE: ANGLE OF REPOSE: FLOWABILITY:	20 degrees 30 - 35 degrees Average
	MATERIALS: Irregular, granular or lumpy materials of medium density, such as anthracite coal, clay, certain mineral ores, etc.
	ANGLE OF SURCHARGE: ANGLE OF REPOSE: FLOWABILITY:	25 degrees 35 - 40 degrees Average
	MATERIALS: Common materials such as bituminous coal, stone, rock, most ores, etc.
Class 4	ANGLE OF SURCHARGE: ANGLE OF REPOSE: FLOWABILITY:	30 degrees Over 40 degrees Sluggish
	MATERIALS: Irregular, stringy, fibrous, interlocking materials, such as bagasse, wood chips, wet earth, tempered foundry sand, etc.