Many smiths believe that quenching N & S prevents warp. It does not. The most common cause of warp is uneven cooling caused by the smith allowing side to side movement in the quench, or the blade being uneven in its proportions, such as being thicker on one side than the other. Another cause is a poor quench medium that allows an uneven vapor jacket around the blade when the hot blade goes into the quench. None of this has anything to do with so called molecular or grain alignment. Once high carbon steel is heated beyond non-magnetic, magnetic attraction will not return until it cools to around 400° when the actual hardening phase begins. In a window of heat range, between 900° and 400°, you can hand straighten any warp you might have, using protection obviously. Some steels such as 01, and A2 can be hand straightened under 400°, but not for but a few minutes. All in all, steel is unaffected by the earths magnetism as far as any internal alignments during it's cool down. One more point. Grain direction. Actual grain direction is only present in bar steel that has been rolled to size and shape at the mill. Once heated much above 1335°, grain shapes turn random without any set direction, and cannot be changed otherwise. What we call grain direction in reality is impurities, and micro voids in the metal that were directionally stretched along with the iron grains during the rolling process. They stay elongated, unaffected by heat, bordered by the random shaped iron grains, and add more strength to the bar especially if that bar will be formed in bends or radical arcs. If the bar is to be used as is, with no bends or radical curving, it is what it is. Other than proper heat treating, nothing else will improve it's qualities.
