For many years, knife manufacturers have been trying to use increasingly harder steel in order to achieve the ultimate cutting edge.  The harder the steel - the longer the knife stays sharp for and the more exquisite the cutting.

The hardness of stainless steel is measured on a scale called Rockwell; 62º being the highest grade commercially available. However, the brittleness of such hard steel has always been a limiting factor.  Very high Rockwell rated steel is likely to chip or break - so manufacturers have settled for softer steel - with a little more 'give'.

I.O.Shen Mastergrade knives have overcome this problem by using a layer of extremely hard steel (Rockwell 62º), which is sandwiched between two layers of softer stainless steel (Rockwell 10º), to produce the ultimate cutting edge.

We call this Triplex Steel Technology.

The only other way of making a high Rockwell rated knife is to use the Damascus method whereby soft steel is heated, folded and then beaten numerous times, making the steel harder and harder with each cycle.  This is called tempering for hardness.  Typically, Damascus knives are manufactured to Rockwell 60 - 62° hardness.  Because each knife is hand made - there will be some very slight variations.

All the knives in the I.O.Shen Mastergrade range (with the exception of the Bread Knife) have used the very latest technology to construct a blade that is not only amazingly sharp but will also retain their edge for a phenomenal amount of time. They have been hand sharpened to a 15º angle, which allows for wonderful slicing and portion control.