Speaking of resinoid grinding wheels, they are commonly used in many workshops. They belong to the category of grinding wheels and are made from abrasives and resin binders. These thin discs are used for grinding ordinary steel, stainless steel, and non-metallic materials. Resinoid grinding wheels are widely used in the production and cutting of ordinary steel, stainless steel, and non-metallic materials. Excellent materials and exquisite craftsmanship ensure high cutting efficiency and economic benefits for different workpieces. However, the characteristics of resinoid grinding wheels can also affect their performance.
1. Abrasive grit size:
Common grit sizes are 22#-80#. Finer grit sizes result in lower cutting efficiency.
2. Resinoid grinding wheel hardness:
Common hardness levels: P, Q, R, N, S; generally, harder diamond grinding wheels are used to reduce wheel wear. The hardness is controlled by factors such as the amount of binder, molding density, firing temperature, and firing time.
3. Abrasive Material:
Commonly used abrasives for resinoid grinding wheels include brown fused alumina (A), white fused alumina (WA), black fused alumina (BA), and black silicon carbide (C). Brown fused alumina is the most commonly used because it has high hardness, high toughness, sharp particles, strong applicability, and a lower price compared to other abrasives. Brown fused alumina is classified into Grade 1 and Grade 2 based on the degree of reduction during smelting, mainly reflected in its chemical composition: Grade 1 has an Al2O3 content ≥ 94.5%; Grade 2 has an Al2O3 content < 94.5%, generally around 85%, and an Fe2O3 content of 4-5%. Therefore, Grade 2 has lower hardness than Grade 1, but also a lower price. Brown fused alumina is suitable for processing various carbon steels and general alloy steels. White fused alumina has higher hardness and greater brittleness than brown fused alumina, and generates less grinding heat. Due to its higher price, it is used when the workpiece requires minimal thermal deformation. It is also used as a mixed abrasive for processing special materials. Black fused alumina has an Al2O3 content of 70-85% and an Fe2O3 content of 7-9%, with low hardness and poor cutting force, but it is also cheaper. Black silicon carbide has high hardness, good brittleness, sharp cutting edges, good self-sharpening properties, and good thermal conductivity, making it advantageous in processing non-ferrous metals, plastics, rubber, and cast iron.
4. Binders:
Commonly used resin binders include: powdered phenolic resin and liquid phenolic resin. Powdered phenolic resin has good processing properties, resulting in slightly lower mold density and slightly larger grain size, but its price is higher than liquid phenolic resin; liquid phenolic resin is cheaper, but the material is prone to clumping, and mixing and spreading the material evenly is difficult, which can lead to localized hardening of the mold.
5. Structure:
The structure number of diamond cutting wheels should be slightly larger to improve cutting efficiency; however, too large a number will affect strength. Commonly used structure numbers are 3 to 7.
Different abrasives are suitable for different materials being cut; therefore, the type of material being cut significantly impacts cutting performance. Generally, corundum abrasive is used when cutting materials with high tensile strength, while silicon carbide abrasive is used when cutting materials with low tensile strength. Users can choose the appropriate resinoid grinding wheel to cut different materials based on their specific needs.
