New barrel bolts not as good as the old ones?

[Judy]

I replaced my wooden hoops (six years and the rivits on the first set were a might loose). The third time I used one, the bolt broke. Luckily I had also ordered replacement bolts at the same time. I broke both of those within a month. In desperation, I pulled the old bolts off of the old hoops, and they are still going strong almost six months later. Has anyone else found the new bolts are not as strong as the older ones?