"I've seen a lot of reviews complaining of malformed rings, and I can't say that I've found any. The rivet seats are clean, and the tools included make opening them, to join rings easy. The riveting tool is proportioned well, so the leverage is good, and the ability to get one's hand around them without losing the rivet is easy."
Chainmail Rings, Mild Steel Flat Rivets for Maille Repair