Tool materials commonly used in tool grinding include high speed steel (HSS), powder metallurgy high speed steel (PM-HSS), cemented carbide (HM) and PCD, CBN, cermets and other superhard materials. High-speed steel cutting tools sharp, good toughness, carbide hardness but toughness is poor. Carbide tool density significantly higher than high-speed steel cutting tools. The two materials are the main material for bits, reamers, milling cutters and taps. Powder metallurgy high-speed steel properties between the above-mentioned between the two materials, mainly used in the manufacture of rough milling cutter and tap.
High-speed steel tool material due to good toughness, so the collision is not sensitive. However, carbide cutting tools, high hardness and brittle, very sensitive to the collision, the edge easy to jump. Therefore, in the grinding process, must be on the operation of carbide cutting tools and placed very carefully to prevent the collision between the tool or tool drop.
As the high-speed steel cutting tools are mostly relatively low precision, the grinding requirements are not high, coupled with its price is not high, so many manufacturers set their own tool shop grinding. Carbide tools, however, often need to be sent to a professional grinding center for grinding. According to Arnold tool grinding center statistics, more than 80% of the tool repair tool is carbide.
Second, the tool grinder
As the tool material is very hard, so the general can only use grinding to change its shape. In the tool manufacturing, grinding in the common tool grinding machine has the following:
Grinding machine: Grinding drill, milling cutter and other tools of the groove or back.
2. Grinding angle machine: grinding cone cone angle (or eccentric rear angle).
3. Repair the edge of the machine: the amendment of the cutting edge of the drill.
4. Universal universal tool grinding machine: grinding cylindrical, groove, back, vertex, horizontal blade, plane, rake face and so on. Commonly used in a small number of complex shape of the tool.
5.CNC grinder: generally five-axis linkage, function determined by the software. Generally used for grinding a large number of high precision, but not complicated tools, such as drill, end mills, reamers and so on. The main suppliers of such grinders come from Germany, Switzerland, the United States, Australia and Japan.
Third, grinding wheel
Abrasive grain
Different grinding wheel material is suitable for grinding different materials of the tool. Different parts of the tool need to use the size of the abrasive particles are different to ensure that the edge protection and the best combination of processing efficiency.
Alumina: Used for grinding HSS tools. The grinding wheel is inexpensive and easily modified into a variety of shapes for grinding complex cutting tools (corundum).
Silicon carbide: used to correct CBN grinding wheel and diamond grinding wheel.
CBN (cubic boron carbide): used for grinding HSS tool. The price is high, but durable.
Internationally, the grinding wheel with B to represent, such as B107, where 107 represents the size of the abrasive grain diameter.
Diamond: used to grind HM tool, the price is high, but durable. D on the wheel to that, such as D64, where 64 represents the size of the abrasive grain diameter.
2. Shape
To facilitate the grinding of different parts of the tool, grinding wheels should have different shapes. The most commonly used are:
Parallel grinding wheel (1A1): grinding angle, diameter, back and so on.