Diamond is harder than CBN - lilyscoggins/ffxivgil GitHub Wiki
A CBN wheel which can be purchased at superabrasivetools is constructed from cubic boron nitride. This material is among the hardest materials available, second just to diamonds. The main feature from the material is that it carries a high abrasion resistance and thermal conductivity that maintains its sharp cutting edges. It’s a most wonderful choice when doing advanced items which require a high awareness of details.
CBN wheels are essential for grinding HSS. This is because it is just a better material for sharpening as well as for durability, one from the best available. Diamond is harder than CBN, but as time passes many people can see that diamond is not a suitable abrasive grain and isn’t your best option when grinding on high-speed dry wheels. Choosing to buy grinding wheels with cubic boron nitrate are able to offer the durability you may need, while providing you with the finished product you need.
CBN grains have 55 times higher thermal conductivity, 4x higher the abrasive resistance and twice the hardness on the aluminum oxide abrasives. This combination makes CBN wheels especially suited to the grinding of high-speed and super-alloy steel tools, providing: long wheel life at high material removal rates; minimum thermal destruction of the technologically advanced because with the cool cutting action; consistent sharp, burr-free cutting edges without having loss of hardness; simple and more effective control of tool sizes, shapes, and finishes and, finally; increased tool grinding productivity on account of less downtime because of wheel breakdown and conditioning, and much less time essential for gauging, spark-out, and wheel changes.
CBN grains will not chemically react with steels and retain their strength above 10000C.Grinding with CBN wheels also adds to the fatigue strength and extends the useful life on the cutting tool at https://www.superabrasivetools.com/diamond-grinding-wheel/. However, before replacing an aluminum oxide wheel using a CBN grinding wheel you have to make sure that the grinding system will take advantage from the productivity potential a CBN wheel offers. The major factors to be considered are: the grinding machine which have to have tight spindle bearings and close fitting slides to get rid of vibration and chatter, constant spindle speed to increase efficiency and reliable feed-rates to preserve wheel life; horsepower requirements material ground with CBN wheels are often hard and require more horsepower to get rid of a given quantity of material from your workpiece , and; the appropriate use of coolant.