<html> <blockquote type=cite cite> Regardless of what folks claim, our tests have shown that V plates are softer - at least for Kawai, Samick and Yamaha. This is what one would expect since V plates have a longer freeze time. The big advantage of V plates is that the longer freeze time results in plates with less distortion and internal stresses. These plates can be 'stuck' into a piano (which is usually how they are installed) without any need for de-stressing.</blockquote> Hi Ron,             I am either mis reading you, or dis agreeing?   Having spent time in the Yamaha foundry.  The V Pro plate is cooled and ready to work in 40mins flat.  The sand cast plate is left in the mold with electrical heating for 24hrs approx.  The slow cooling gives the stress relief required to prevent distortion.   The rate of cooling also effects the structure of the free carbon crystals.  I have heard stories about aging plates, out side in the elements for extended periods, for further stress relief.   This may be sales smoke and mirrors. The water in the sand, quenches the melt on contact, and case hardens the material to a depth of about 1mm.   So the skin of a sand cast plate is much harder. It's the addatives in V Pro that enables the material to be cooled this rapidly.  Unless you know the composition, there is no way to look up Brinell or Rockwell hardness tables to verify this.   My gut feel is that the skin of sand cast is much harder, but if over grinding has taken place, to bite into the raw grey iron, then the reverse may be true. Regards Roger </html>