抄録
The surface crack observation by a plastic replica method is an indispensable technique to study initiation, propagation and non-propagation of a micro crack. In particular it is difficult to pinpoint the place in which the crack will initiate for smooth specimen. For the case, it is the only way to observe going back in time, after finding a large crack. A replica method makes this possible. In this report, the revealed matters which are made clear in the surface observation by the replica method are discussed
