The selection of lapping tool material shall be determined by the material and performance of valve grinding parts. The lapping tool material shall have the characteristics of fine and uniform structure, good sand embedding performance, good wear resistance, sufficient stiffness, no deformation, and its hardness is softer than that of the abrasive part.

选择研具材料应由阀门研磨件的材质及性能而定。研具材料应具有：组织细密均匀，嵌沙性能好，有良好的耐磨性，足够的刚度，不变形，其硬度比研磨件要软的特性。

The selection of lapping tool material shall be determined by the material and performance of valve grinding parts. The lapping tool material shall have the characteristics of fine and uniform structure, good sand embedding performance, good wear resistance, sufficient stiffness, no deformation, and its hardness is softer than that of the abrasive part.

通常用于做研具的材料有如下几种。

There are several materials commonly used as lapping tools.

铸铁：铸铁含有片状石墨，其耐磨性和润滑性好，强度也高，它还具有成本低，易加工等优点。因此，铸铁研具适于研磨像硬质合金、淬硬钢、有色金属等多种材料的工件，也适用于敷砂研磨、嵌砂研磨和夹砂布研磨。铸铁具使用的材料有灰口铸铁和球墨铸铁，一般硬度为HB120～220。铸铁研具能确保质量，同时研磨的效率高，使用普遍。

Cast iron: cast iron contains flake graphite, which has good wear resistance, lubricity and high strength. It also has the advantages of low cost and easy processing. Therefore, cast iron grinding tools are suitable for grinding workpieces of various materials such as cemented carbide, hardened steel and non-ferrous metals. They are also suitable for sand coating grinding, sand embedding grinding and abrasive cloth grinding. The materials used for cast iron tools include gray cast iron and nodular cast iron, with a general hardness of hb120 ~ 220. Cast iron grinding tool can ensure the quality, at the same time, the grinding efficiency is high, and it is widely used.

低碳钢：低碳钢的韧性比铸铁大，能适应铸铁难得研磨的细长圆孔、圆锥孔、螺纹等工件，低碳钢一般作粗研材料。

Low carbon steel: the toughness of low carbon steel is greater than that of cast iron. It can adapt to slender round holes, conical holes, threads and other workpieces rarely ground by cast iron. Low carbon steel is generally used as rough grinding material.

铜：铜韧性大，耐磨性好，适于加工余量大粗糙度要求低的工作的粗研阀门，能起低碳钢研具的作用（但成本高，一般极少采用）。

Copper: copper has large toughness and good wear resistance. It is suitable for rough grinding valves with large machining allowance and low roughness requirements. It can play the role of low carbon steel grinding tool (but it is rarely used due to high cost).

铝：铝质地比铜软，适用于铜等软金属的精细研磨。

Aluminum: aluminum is softer than copper. It is suitable for fine grinding of soft metals such as copper.

铅、巴氏合金：适用于抛光和研磨软钢或其他软质材料的工件。

Lead and Babbitt alloy: suitable for polishing and grinding workpieces of mild steel or other soft materials.

玻璃：玻璃质地硬脆，适用于工件的研磨和抛光，特别是淬硬钢的精研。

Glass: glass is hard and brittle. It is suitable for grinding and polishing of workpieces, especially for fine grinding of hardened steel.

沥青：沥青质地软，适用于玻璃、水晶等脆硬材料的研磨和抛光船用阀门，也适用于淬硬钢的精抛光加工。沥青对工件形状适应性强。

Asphalt: asphalt is soft and suitable for grinding and polishing of brittle and hard materials such as glass and crystal. It is also suitable for fine polishing of hardened steel. Asphalt has strong adaptability to workpiece shape.

皮革、毛毡、涤沦织物：质地柔软，常用于抛光工件。涤沦织物平整均匀，衬垫在平整的研具上，精研和抛光的效果好。

Leather, felt, polyester fabric: soft texture, commonly used for polishing workpieces. The polyester fabric is flat and uniform, and the pad is on the flat grinding tool, which has a good effect of fine grinding and polishing.

为了节省材料、减少研具，研具常常制成两用的，既可敷涂研磨剂，又可衬托砂布或砂纸。专门衬托砂布或砂纸的研具，一般用碳钢、铸铁制成。

In order to save materials and reduce grinding tools, grinding tools are often made into dual-purpose tools, which can not only apply abrasive, but also set off abrasive cloth or sandpaper. Grinding tools specially used to set off abrasive cloth or sandpaper are generally made of carbon steel and cast iron.