3 KudoZ points awarded for this answer. Comment: "You're right! Too literal. I think your second suggestion is the best one ("binding device"). Using "machine" might give the impression that it a separate farm implement, whereas I think bindeapparatet is meant to be part of the hay-baler. I'm thinking this in part because "binders" are apparently mostly obsolete instruments in and of themselves. Thanks again, this helps enormously."