Standard for turning tool grinding

Turning tool (refers to the integral turning tool and welding turning tool) with blunt re - grinding is grinding on the grinder. Alumina grinding wheel for grinding HSS turning tool (white), silicon carbide grinding wheel for grinding hard alloy tool head (green).

The characteristics of grinding wheel are determined by abrasive, particle size, hardness, bond and structure.

1. The abrasive

Commonly used abrasives are oxides, carbides and high hard abrasives. Alumina and silicon carbide grinding wheels are commonly used on ships and in factories. Alumina grinding wheel grain hardness is low (HV2000-HV2400), toughness, suitable for grinding high speed steel turning tool, white is called white corundum, gray brown is called brown corundum.

The abrasive hardness of silicon carbide grinding wheel is higher than that of alumina grinding wheel (Hv2800). Brittle and sharp, and has good thermal conductivity and electrical conductivity, suitable for grinding hard alloy. Black and green silicon carbide grinding wheels are commonly used. The green silicon carbide grinding wheel is more suitable for grinding carbide turning tools.

2. The particle size

Grain size indicates the degree of abrasive grain size.

The number of holes per inch in length through which the abrasive grain can pass is used as a symbol. For example, the size of 60 means that the abrasive can pass through a screen with 60 holes per inch in length. Therefore, the higher the number, the finer the abrasive grain. Coarse grinding tool should be selected with small grinding grinding wheel, fine grinding tool should be selected with large grinding wheel (fine grinding wheel). Commonly used on board are medium soft or medium hard grinding wheels with particle sizes of 46 to 0.

3. The hardness

The hardness of grinding wheel reflects the degree of difficulty that the abrasive particles fall off from the surface of grinding wheel under the action of grinding force. Grinding wheel hard, that is, the surface abrasive particles difficult to fall off; If the grinding wheel is soft, the abrasive grains fall off easily. The hardness of grinding wheel and the hardness of abrasive grain are two different concepts, which must be distinguished clearly. Soft or medium soft grinding wheel should be selected when grinding HSS turning tool and carbide turning tool.

In addition, the bond and structure of grinding wheel should also be considered when choosing grinding wheel. Ceramic bond (code A) and medium-size grinding wheels are generally used on ships and in factories.

To sum up, we should choose the grinding wheel correctly according to the tool material. Soft or medium soft alumina grinding wheel with particle size from 46 to 60 should be used for grinding HSS turning tools.

When grinding hard alloy turning tool, soft or medium soft silicon carbide grinding wheel with particle size from 60 to 80 should be selected.