We study properties of Fe K lines of a large sample of Seyfert 1s observed by ASCA .
Fits with power laws and Gaussian lines yield the average linewidth and equivalent width of 0.22 \pm 0.03 keV and 0.13 \pm 0.01 keV , respectively .
Thus , the typical lines are weak and narrow .
We then obtain the average line profile of all our spectra , and find it to consist of a narrow core and blue and red wings , with the red wing being much weaker than that of , e.g. , MCG –6-30-15 .
We obtain three average spectra of Seyferts grouped according to the hardness , and find the equivalent width of the core ( originating in a remote medium ) to be \simeq 50 eV in all three cases .
The wings are well fitted by a broad line from a disc with strong relativistic effects .
Its equivalent width correlates with the slope , increasing from \sim 70 eV for the hardest spectrum to \sim 120 eV for the softest one .
The inner disc radius decreases correspondingly from \sim 40 to \sim 10 gravitational radii , and the fitted disc inclination is \sim 45 \degr .
The obtained correlation between the slope and the strength of the broad Fe K line is found to be consistent with the previously found correlation of the slope and Compton reflection .