You can resharpen them as long as they dont get all dinged up. The thing about replacable blade heads is that the blade edges are so thin that the get bent and dinged up easialy, thats why they are replacable. Ive personaly shot a striker into my block target upwards of 30 to 40 times and it would still shave the hair off my arm. I would just pick up a back of replacement blades, but under some instances you can touch up old blades.