ISO 18549-2:2009 describes two methods for the determination of the time (flow rate) it takes for a given quantity of a heated powder mix, based on iron or steel powders and to be used for warm compaction, to pass through a funnel with a given orifice diameter.

Method A uses a funnel with an orifice of 2,5 mm and a test portion of 50 g and is, to a large extent, based on the method standardized in ISO 4490:2008. The method can only be used for powder mixes that flow freely through the 2,5 mm orifice in the heated condition.

Method B uses a funnel with an orifice of 5 mm and a test portion with a size of 150 g.

Both methods cover a testing temperature range of 60 °C to 180 °C and either of them can be selected after agreement between the parties involved.