This part of ISO 18549 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. 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.