There are other references also to blades being brittle (see Foster in Bronson, 1986, 25 for a 17th century mention). Since there were so many variations in the production of crucible steel, some were bound to be of lesser quality. Also we do not know if the blades that break are hypereutectic with spherical cementite to make the pattern, or were they hypoeutectic and had a ferrite pearlite banding? I think there is also a mention about how you should not get a blade that has a pattern that goes across the width of the blade. This makes sense because of crack propagation and it could spread across the blade. As far as I remember, crucible steel is never quenched, as this would destroy the pattern. The steel has to be forged below red heat to keep the pattern. Low temperature tempering can be done in oil, or as some references say...in a fat Nubian slave, or in the wind while riding on horseback. Also, as already noted, the matrix of the blade can be very different too, usually pearlite, ferrite or DET (divorced eutectic transformation). No exampes of crucible Damascus steel blades which have been examined and published have tempered martensite. One of the theories of why they are so strong is that if you do have a crack, when it hits the spherical cementite the force is spread and the crack stops. Oh, as far as how far north...we also have unpublished crucible steel blades from Western Siberia, which got there via trade.
