Sometimes, the real world doesn’t behave according to plan. Ring any bells? Fasteners are the same. We can – often strictly speaking from experience – tell you whether or not a given fastener is going to work. This makes it easier for us to decide what tests need to be done, and this saves us all a lot of time.
Of course everything is strictly documented and dutifully analyzed. Experience never gets in the way of the eagerness to develop and learn new things.