  Black hole systems, comprised of a black hole, accretion disk, and collimated
outflow are studied here. Three AGN samples including 753 AGN, and 102
measurements of 4 GBH are studied. Applying the theoretical considerations
described by Daly (2016), general expressions for the black hole spin function
and accretion disk magnetic field strength are presented and applied to obtain
the black hole spin function, spin, and accretion disk magnetic field strength
in dimensionless and physical units for each source. Relatively high spin
values are obtained; spin functions indicate typical spin values of about (0.6
- 1) for the sources. The distribution of accretion disk magnetic field
strengths for the three AGN samples are quite broad and have mean values of
about $10^4$ G, while those for individual GBH have mean values of about $10^8$
G. Good agreement is found between spin values obtained here and published
values obtained with well-established methods; comparisons for 1 GBH and 6 AGN
indicate that similar spin values are obtained with independent methods. Black
hole spin and disk magnetic field strength demographics are obtained and
indicate that black hole spin functions and spins are similar for all of the
source types studied including GBH and different categories of AGN. The method
applied here does not depend upon any specific accretion disk emission model,
and does not depend upon a specific model that relates jet beam power to
compact radio luminosity, hence the results obtained here can be used to
constrain and study these models.
