Over the years we have often debated and discussed different faults and flaws in blades. Two recent posts about swords for sale have raised a number of questions again and I wondered if it was worth revisiting this subject to gain peoples views/understanding about them I would like to consider the following: 1. What is a fatal flaw 2. What is a fault? when is it acceptable? and at what point does it convert in to a fatal flaw?   To start discussion I would offer the following opinions: 1.