  We have calculated the one-loop supersymmetric corrections to the 2 to 2
parton scattering subprocesses antiq q to antiq q, antiq q to g g, g q to g q
and g g to g g, including form-factor corrections and box diagrams with
internal squarks and gluinos of arbitrary mass. In general, these exhibit cusps
at the corresponding direct-channel sparticle thresholds. We use these
calculations to make numerical estimates of the possible threshold effects at
the Fermilab Tevatron collider and at the LHC, which depend on the rapidity
range selected, but can be as large as a few percent. These effects are diluted
in the integrated large-E_T cross section, where they are negative.
