Bar BORIDE Golden Star 320grit 150x25x6mm

Bar Boride GOLDEN STAR 320 grit, series GOLDEN STAR has a standard size of 152x25x6mm (6”x1”x1/4”). The average grain size in sieving is about 30 microns. The stone of the Coarse category is intended for the final stages of peeling when forming chamfers on a new cutting tool, repairs (removal of notches and chips) and starting sharpening operations. Can be used either as an initial stone in the process of grinding previously sharpened and blunted cutting tools, or to remove scratches from coarser stages of roughing, for example, after a 220 grit stone. The recommended grit for the 320 grit step following the Boride GOLDEN STAR stone is 400 grit (ANSI) Boride GOLDEN STAR.
Grinding stones manufactured by Boride Golden Star EDM series belong to one of the latest developments of BORIDE Engineered Abrasives. The abrasive grain of this stone is aluminum oxide, the bond is ceramic. As you know, each series of abrasive stones from Boride has its own distinctive features and also its highly specialized application. The main purpose of the Golden Star series is the processing of carbon steels. Among the features that distinguish this series in Boride products, I would like to note two.
The first is the more stringent requirements for the sieving of aluminum oxide abrasive grains, which implies a more careful selection in terms of composition and minimization of tolerances in terms of parameters. As a result, the abrasive in the bars of the Golden Star series is located more densely, the working surface is a more regular structure with a uniform, uniform distribution of similar grains in the working area. This feature explains the fact that Golden Star EDM, unlike other series of Boride cameos, has only 7 levels of grit of abrasive bars: 150; 220; 320; 400; 600; 800 and 1000 grit. The effect is the same as in Arkansas abrasives, when a relatively coarse grain (in Arkansas on average about 6 microns) works finer than a stone with a much finer abrasive. This is due to the fact that the grains have a small spread in size and evenly and densely exit with their tops into the working area of ​​the bar.
The second feature is rarely mentioned, but it significantly affects the comfort of working with abrasives of this series. The intergranular space in the Golden Star bars is impregnated with a special anti-friction compound.
If we talk about the work of the Boride bars of the Golden Star EDM series with various lubricating fluids, then in fact any coolant, both water-based and oil-based, can be used with these stones. Boride develops its own lubricating fluids and recommends using them, because in combination with the anti-friction impregnation composition of the stone, they give the best result. Water or soapy water is suitable for working with this series of stones, but often does not combine well with the processing of carbon steels (which, in fact, the Golden Star series is intended to work with) due to the possible formation of rust.
Boride stones of the Golden Star EDM series do not require special care, which differs from the regulations provided for other abrasives. You can clean and wash the stones in water using a brush and soapy water. Alignment of working surfaces is carried out on glass using silicon carbide powder. Store stones preferably in a wooden organizer made of planed non-coniferous wood.