Originally Posted by
quilting cat
Rotary blades also come with a thin coat of oil, which helps them move against the handle. They should be fine in original sealed packaging. I have also used hand sewing needles that are decades old, and only find rusty pins inserted in fabric.
I had some rotary blades from Harbor Freight. Unopened in the original packaging. The oil sort of dried up, leaving a gunky, sticky film on the blades. I don't know if the same thing could happen to quality blades.