  Spectroscopy for 247 stars towards the young cluster NGC 346 in the Small
Magellanic Cloud has been combined with that for 116 targets from the
VLT-FLAMES Survey of Massive Stars. Spectral classification yields a sample of
47 O-type and 287 B-type spectra, while radial-velocity variations and/or
spectral multiplicity have been used to identify 45 candidate single-lined
systems, 17 double-lined systems, and one triple-lined system. Atmospheric
parameters (T$_eff$ and log$g$) and projected rotational velocities
($v_e$sin$i$) have been estimated using TLUSTY model atmospheres; independent
estimates of $v_e$sin$i$ were also obtained using a Fourier Transform method.
Luminosities have been inferred from stellar apparent magnitudes and used in
conjunction with the T$_eff$ and $v_e$sin$i$ estimates to constrain stellar
masses and ages using the BONNSAI package. We find that targets towards the
inner region of NGC 346 have higher median masses and projected rotational
velocities, together with smaller median ages than the rest of the sample.
There appears to be a population of very young targets with ages of less than 2
Myr, which have presumably all formed within the cluster. The more massive
targets are found to have lower $v_e$sin$i$ consistent with previous studies.
No significant evidence is found for differences with metallicity in the
stellar rotational velocities of early-type stars, although the targets in the
SMC may rotate faster than those in young Galactic clusters. The rotational
velocity distribution for single non-supergiant B-type stars is inferred and
implies that a significant number have low rotational velocity ($\simeq$10\%
with $v_e$<40 km/s), together with a peak in the probability distribution at
$v_e \simeq$300 km/s. Larger projected rotational velocity estimates have been
found for our Be-type sample and imply that most have rotational velocities
between 200-450 km/s.
