The hardness of the abrasive agent is added depends on the amount of binding and the density of abrasive, abrasive grains easily fall off indication low hardness; vice versa, which means high hardness. Hardness level is generally divided into super-soft, soft, medium soft, medium, medium-hard, hard and superhard seven magnitude, from these levels can be subdivided in a number of small magnitude. Abrasive hardness measurement methods are more commonly used hand cone, mechanical cone method, Rockwell hardness measurement method and sandblasting assay. The hardness of the abrasive and its dynamic modulus of elasticity has a corresponding relationship, which is conducive to the audio abrasive measured dynamic elastic modulus of said abrasive tools. In the grinding process, if they are grinding workpiece material hardness, generally used in low hardnesscoated abrasive; Conversely, the selection of high hardness Bonded abrasives
The original abrasives - ore, blasting the health of workers involved, so that countries have drawn up regulations prohibit silica ore containing 1% or other similar substance on the free silica as abrasive blasting material. In the UK we are fortunate to have expendable mill buildings can meet the requirements of health and safety regulations, and some even meet the most stringent requirements of the U.S. Navy. Expendable abrasive industry has always been concerned about the development of new products to meet market demand. Currently, the UK market for the consumption of abrasives, mainly copper values, cinder and olivine. Copper slag is relatively inexpensive, readily available, compact, with sharp and consistent quality crystal. Water quenching molten slag, copper refining method to get into a black transparent material particles. This quenching the molten material effective to stabilize the composition in the glassy slag, the slag in the grain boundary even allow slow cooling, and often does not allow the metal accumulation. After the slag from the furnace, copper slag processing by evaporation, and its copper and zinc reduced to very low levels. Essentially copper slag containing iron silicate minor amounts of other metals, the content of toxic metals in the required range. Particle size of 0.15 to 1.71 Knife 'no slag or cinder, also known as the iron silicate, power plant from Western Europe. Cinder lighter in color and density than copper slag small. Cinder copper slag blasting to white than some, but the surface is not necessarily smooth, cinder dust generated due to light-colored and black copper slag generated dust. In abrasive blasting, coating material must be performed before blowing brush, vacuum cleaners and other processes. Cinder, a toxic metal content is generally low, it is superior to copper slag, are available for a variety of specifications.