Research Report RR:D05-1039 Research Report D05-1039 presents the results of a proficiency test program used to establish precision and bias statements for metallurgical coke for ASTM D3173, Standard Test Method for Moisture in the Analysis Sample of Coal and Coke; D3174, Standard Test Method for Ash in the Analysis Sample of Coal and Coke; D3175, Standard Test Method for Volatile Matter in the Analysis Sample of Coal and Coke and D4239, Standard Test Method for Sulfur in the Analysis Sample of Coal and Coke Using High Temperature Tube Furnace Combustion Methods. The proficiency program included 20 laboratories which conduct analysis of metallurgical coke on a routine basis. A selection of furnace coke, foundry coke and coke breeze samples was distributed through the program over a 12 year period. All data was collected in accordance with the principles of ASTM E691 Standard Practice for Conducting an Interlaboratory Study to Determine the Precision of a Test Method. The research report presents summary method performance statistics as well as the measurement data used to calculate the precision and bias statements.