It might be hard to give a speedy answer considering how many years have passed since the beginning. There are many variables. You can also ask how many rounds you can expect from a set. The level and the frequency of your games will determine the replacement period. For low-handicappers and regular players, it's a better idea to upgrade your set of irons every 300 rounds, or about 4 to 5 years. This will keep the clubs in good condition and prevent them from wearing out where you hit the ball. Even casual golfers who aren't that competitive can keep their clubs for up to 8 years. 10 years is a good limit before technology takes over.