  On behalf of the International Astronomical Consortium for High Energy
Calibration (IACHEC), we present results from the cross-calibration campaigns
in 2012 on 3C 273 and in 2013 on PKS 2155-304 between the then active X-ray
observatories Chandra, NuSTAR, Suzaku, Swift and XMM-Newton. We compare
measured fluxes between instrument pairs in two energy bands, 1-5 keV and 3-7
keV and calculate an average cross-normalization constant for each energy
range. We review known cross-calibration features and provide a series of
tables and figures to be used for evaluating cross-normalization constants
obtained from other observations with the above mentioned observatories.
