They are designed to thresh rice . Spikes do, in my opinion, better in beans. You cannot cut corn because it will bust up the cob instead of just rolling them thru.
Yes you can cut corn with them, and can do a very good job. We have never run a rasp, and have gone from JD55's to 9600's. Keep good spikes, and for corn you can, not necessary, take out the bottom spikes and replace them w_ some 5_8" bolts, threads down. I will cut as clean, and have as good a sample as a rasp. Guaranteed.