New tines are not sharp like a knife, they are beveled so the edge cuts into the soil. As they wear, eventually the cutting edge gets rounded and becomes difficult to rip into the soil. At that point, cutting a bevel similar to the way a lawnmower blade is sharpened will make them effective again. As they wear further, they get thin, sharply pointed, and almost sharp like a knife. At that point, they are no longer doing the job and should be replaced. You don’t sharpen them like a knife, rather, like a lawn mower blade with a flat bevel at about 35 to 40 degrees. I’ve never sharpened more than one time on a set of tines because they were replaced the next go around.
I’m never a “my way or the highway” person. You do you. I’ll do me. I like my tools to perform at their best. Using a tiller with good tines is a lot less work.
Also, I see that off-brand 3 hole tine in your picture.
