Rolled ball screw vs ground ball screw DLY

According to manufacturing processes, ball screws are mainly divided into Ground Ball Screws and Rolled Ball Screws.

This article will systematically compare the two from multiple perspectives including manufacturing process, accuracy, surface quality, length and customization capability, strength and life, cost, and applicable scenarios, providing comprehensive reference for engineers and purchasing personnel.

Ground ball screws use precision grinding processes. After rough machining of the blank, ultra-precision thread grinding machines are used for step-by-step grinding, processing a small amount of threads each time to ensure extremely high accuracy and smooth surface. During grinding, the thread and end shaft are processed using the same reference center to ensure concentricity and straightness. Heat treatment can be performed before or after grinding to eliminate internal stresses in the material and improve nut fit accuracy and thread geometric stability.

This process is complex and time-consuming (30–45 days), suitable for medium to short stroke, high-precision, and customized applications, such as high-end CNC machines, semiconductor equipment, and high-load automation systems.

Rolled ball screws form threads through a cold rolling process. Circular bars are repeatedly pushed between rolling dies, causing plastic deformation of the material to form threads without removing material, resulting in very high production efficiency, suitable for large-scale standard part production.

After rolling, heat treatment is performed to improve surface hardness and strength. Due to slight thread deformation caused by heat treatment, the accuracy of rolled screws is slightly lower.
This process is suitable for mass production and long-stroke applications.

Comparison of ground ball screw and rolled ball screw — Ground vs rolled ball screw

Precision ground ball screws can reach C0-C5 accuracy grades, with high repeatability.

The concentricity and straightness between the thread and end shaft are well controlled, achieving micron-level precision (for example, C0 grade 100mm stroke deviation is only 0.003mm).

Precision rolled ball screws have an accuracy grade of C7-C10, and in very few cases can stably reach C5.

Although the accuracy is lower than that of ground ball screws, it can still ensure smooth linear motion in most industrial applications.

Precision ground ball screws are suitable for high-precision, high-load, and high-repeatability applications, such as high-end CNC machines, semiconductor equipment, and high-precision automation systems.
Precision rolled ball screws are more suitable for industrial applications with general precision requirements, cost sensitivity, and mass production, such as conveyor equipment, ordinary machine tools, and basic automation systems.

The thread surface of ground ball screws is smooth, with roughness reaching Ra 0.2–0.4 μm, low friction, low noise, strong wear resistance, and smooth operation.

The surface of rolled ball screws needs to be polished to remove the oxide layer; otherwise, friction increases and mechanical efficiency decreases. The polishing quality directly determines the operational smoothness and wear resistance of rolled ball screws.

Roller ball screws, due to plastic deformation from rolling, have tensile strength increased by 20–30% and life extended by about 50%.
Ground ball screws achieve hardness and strength through heat treatment, with controllable strength, but the fatigue life is slightly lower than rolled screws in high-load and long-stroke applications.

Ground ball screws are limited by grinding machines and processing technology, usually used for medium to short stroke applications, with limited custom length.
Roller ball screws are highly customizable in length, and can be produced in lengths over 6 meters, suitable for long-stroke or specially customized equipment, greatly expanding design freedom.

Ground ball screws are complex to manufacture, with long lead times (usually 30–45 days) and a high unit cost, so the ground ball screw price is relatively higher, making them suitable for small batch customized applications.

Rolled ball screws have high production efficiency and low cost, so the competitive price rolled ball screw makes them suitable for large-scale standard parts with a high cost-performance ratio.

In general, ground ball screws are suitable for high-precision, high-load, high-repeatability, and strongly customized applications, while rolled ball screws are more suitable for mass production, general precision requirements, long stroke, or cost-sensitive industrial applications.

Engineers should comprehensively consider accuracy requirements, load capacity, length, life, surface quality, cost, and delivery time when selecting ball screws. For high-precision equipment, ground ball screws are the first choice; for large-scale general industrial applications, rolled ball screws are an economical and efficient solution.

Ground vs rolled ball screw each have advantages:

Ground Ball Screw: micron-level accuracy, excellent repeatability, low friction, low noise, high surface quality, suitable for high-precision and customized requirements.
Rolled Ball Screw: high production efficiency, low cost, high strength, length customizable over 6 meters, suitable for mass production, long-stroke, and cost-sensitive industrial applications.

When choosing ball screws, one should consider application requirements, accuracy, length, load, life, cost, and delivery time, balancing performance and economy to select the most suitable solution.
After reading this guide on the differences between ground and rolled ball screws, you will have a clearer understanding of how to choose the ball screw type that best meets your needs. To learn more about engineering knowledge of different types of ball screws, please contact us.

We will help you weigh the advantages and disadvantages of different types of ball screws and provide the most suitable type for your project.

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