I don't think there's that big of range. From 10 to 18 TPI every even number, IIRC. With the smooth action of a band saw I'd use the coarsest one that will do the work. Obviously that would not be a 10 on thick bar stock. But then again, some soft alloys and the right cutting fluid and that might be the best combo.
I have some wood cutting as well, maybe they are 8 TPI?