  We present deep SCUBA-2 450 micron and 850 micron imaging of ten strong
lensing clusters. We provide a >4-sigma SCUBA-2 850 micron catalog of the 404
sources lying within a radius of 4.5' from the cluster centers. We also provide
catalogs of the >4.5-sigma ALMA 870 micron detections in the clusters A370,
MACSJ1149.5+2223, and MACSJ0717.5+3745 from our targeted ALMA observations,
along with catalogs of all other >4.5-sigma ALMA (mostly 1.2 mm) detections in
any of our cluster fields from archival ALMA observations. For the ALMA
detections, we give spectroscopic or photometric redshifts, where available,
from our own Keck observations or from the literature. We confirm the use of
the 450 micron to 850 micron flux ratio for estimating redshifts. We use lens
models to determine magnifications, most of which are in the 1.5-4 range. After
supplementing the ALMA cluster sample with Chandra Deep Field (CDF) ALMA and
SMA samples, we find no evidence for evolution in the redshift distribution of
submillimeter galaxies down to demagnified 850 micron fluxes of 0.5 mJy. Given
this result, we conclude that our observed trend of increasing F160W to 850
micron flux ratio from brighter to fainter demagnified 850 micron flux results
from the fainter submillimeter galaxies having less extinction. However, there
is wide spread in this relation, including the presence of some optical/NIR
dark galaxies down to fluxes below 1 mJy. Finally, with insights from our ALMA
analysis, we analyze our SCUBA-2 sample and present 55 850 micron-bright z>4
candidates.
