  We present results from a BeppoSAX (July 2001) observation of the FRI radio
galaxy NGC6251, together with a re-analysis of archival ASCA (October 1994) and
Chandra (September 2000) data. The weak detection above 10 keV and the lack of
iron fluorescent K-alpha emission lines in the BeppoSAX spectrum rule out that
the bulk of the X-ray emission is due to an obscured Seyfert nucleus. The study
of the multiwavelength spectral energy distribution suggests instead that
X-rays probably originate as inverse-Compton of synchrotron seed photons in a
relativistic jet, indicating that NGC6251 hosts a low radio luminosity [L(5
GHz) ~10^40 erg/s] blazar. The BeppoSAX spectrum is flatter than in the earlier
ASCA observation. This might be due to the emergence of a different spectral
component during phases of lower X-ray flux. In this context, we discuss some
possible explanations for the intense and mildly-ionized fluorescent iron line
measured by ASCA.
