
I've had no problems with it. I bought an AP 4980 air hammer (known as "big bad" to those who watch South Main Auto on YouTube) and I bought these parts to work with. I know other customers have had bad experiences, but my experience was the opposite. Maybe others had a bad batch? Anyway, for those familiar with the AP 4980, this is a real jackhammer and I have used these bits with this jackhammer for auto work and concrete breaking. I'm not a professional, but I'm very picky about my tools and have high expectations. To be clear, I expect I'll never have to buy another set of chisels again. If I do I will change this review. So far my expectations have been met.