As stated in DGR 184.108.40.206.2 Step 6 (a), Dangerous Goods Declarations must show the “Net Quantity”. The definition of ”Net Quantity” is stated in Appendix A. The “Net Quantity” is either the volume or weight of the dangerous goods described in the Proper Shipping Name. The Proper Shipping Name of UN 3528 is Engine or Machinery. Therefore, the net weight of the Engine or the Machinery must be used to indicate the “Net Quantity”. You can continue to use the net weight in making the declaration. Furthermore, the 25 kg rule of US State Variation USG-13 will apply to Engines and Machinery in Class 3, however US FAA has mentioned that until the rules in 49CFR gets amended, FAA will not take action against shipments prepared under ICAO TI 2017-2018.