The screw has a precision ball screw with high-precision grinding (accuracy is divided into 6 grades from CO-C7) and a cold-rolled ball screw bearing formed by high-precision cold rolling (accuracy is divided into 3 grades from C7-C10)
What's the difference between the both screws?
- Different Processing Methods
The cold-rolled ball screw is first cut out a certain depth of grooves on the polished rod material, and the groove pitch is equal to the wire pitch you want to process, and then rolled out by a rolling mill. The grinding screw is to use a special cylindrical grinder to precisely process the shape and size of the arc groove on the basis of pressing, but the cut groove is at the bottom of the arc groove.
- Different Scope of Application and Cost
The precision grade of the rolling screw is medium and low, and it is suitable for ordinary equipment with low precision requirements. It has a short life and high efficiency, but the cost is also low. The precision level of the grinding screw is medium to high, which is suitable for equipment with high precision requirements such as CNC machine tools. It has high precision, long life and high efficiency, but also high cost.
- Different Appearance Details
The cold-rolled screw is extruded, and the grinding grade, as the name suggests, is processed by grinding. The transformation process is different from the grinding process, and there are traces of craftsmanship after it comes out naturally. The surface of cold-rolled screw is generally smooth and shiny, and the reflectivity is high and dazzling under light conditions. The grinding marks of the grinding wheel can be seen carefully on the surface of the grinding screw. In terms of appearance, the raceway groove of the remanufactured lead screw is smooth and shallower than that of the ground lead screw. Roller-grade ball screw raceways generally have a small groove on the top of the bulge between the raceway grooves.
- Different Precision
The precision of the grinding ball screw is generally below C7 (±50/300MM)
The precision of rolling ball screw is above C7 (±50/300MM)
So when we use the grinding ball screws for pick and place machine, it is high precision, reversibility, high efficiency and more durable, which can maintain long-term stable placement and ensure the X and Y axis are not offset.