Trapezoidal Screws VS Ball Screws: What is the Difference?

Trapezoidal Screws and Ball Screws are two common transmission components with significant differences in structure, working principle, performance characteristics and application scenarios, as follows:

Structural Differences

Trapezoidal Screw: The structure is relatively simple, consisting of a metal rod (screw) with trapezoidal threads and a trapezoidal nut. The contact between the nut and the screw is sliding friction.
Ball Screws: The structure is more complex, consisting of a screw, a nut and a ball. The ball acts as a rolling element, rolling between the threaded raceways of the screw and the nut to realize rolling friction between the screw and the nut.

Difference in working principle

Trapezoidal Screw: As the screw rotates, the nut moves axially along the screw through sliding friction with the screw. This sliding friction mode of operation results in relatively low transmission efficiency.
Ball Screws: When the screw rotates, the ball rolls in the threaded raceway to roll and circulate, driving the nut to move along the axial direction of the screw. The working mode of rolling friction greatly improves the transmission efficiency.

Comparison of Performance Characteristics

Trapezoidal Screws: Lower cost for applications with limited budgets. Low transmission efficiency, generally around 26% to 46%. High friction, generating much heat and relatively short service life. With self-locking function, applicable to the need for self-locking occasions, but the precision is relatively low, to meet the needs of some applications that do not require high precision.
Ball Screw: Higher cost, but due to high efficiency and long service life, it may be more economical in the long run. Transmission efficiency is up to 90% or more, reducing energy loss. Low friction, less heat generation and long service life. No self-locking function, but self-locking can be realized by other mechanical designs. High precision, repeatable positioning accuracy up to micron level, suitable for applications requiring high precision.

Differences in application areas

Trapezoidal Screw: Suitable for applications that do not require high precision, but require large load carrying capacity or self-locking function. Commonly used in construction scaffolding lifting systems, hand tools and simple mechanical lifting devices.
Ball Screws: Widely used in applications with high requirements for precision, efficiency and service life. Commonly used in CNC machine tools, automation equipment, precision measuring instruments, robot joints and semiconductor manufacturing equipment.

What factors should be considered when choosing a trapezoidal screw or ball screw?

When selecting Trapezoidal Screws or Ball Screws, the following factors should be considered:

1.Precision requirements

High-precision applications: such as CNC machine tools, semiconductor manufacturing equipment, CMMs, etc., which require precise control of displacement and positioning, Ball Screws are the first choice, and their repetitive positioning accuracy can be up to micron level.
Low-precision applications: For some occasions that do not require high precision, such as common lifting platforms, manual adjustment mechanisms, etc., Trapezoidal Screws are able to meet the requirements, and the cost is low.

2.Load capacity

Large loads: If large axial loads need to be borne, both Trapezoidal Screws and Ball Screws have corresponding specifications to choose from. However, Trapezoidal Screws have a relatively large load capacity for the same size because they have a larger thread profile and can withstand greater pressure. For example, Trapezoidal Screws are often used in elevators for large building construction.
Small and Medium Loads: Ball Screws have high efficiency and precision under small and medium loads, and are suitable for scenarios such as drives for automated production lines and joint drives for small robots.

3.Transmission efficiency

High-efficiency transmission: The transmission efficiency of Ball Screws can be as high as 90% or more, which can effectively reduce the energy loss, and perform well in the equipment requiring frequent starting and stopping and high-speed operation, such as high-speed machining centers, automated logistics and conveying equipment, and so on.
Not high efficiency requirements: trapezoidal screw transmission efficiency is low, generally in 26% – 46%, but in some of the speed requirements are not high, power consumption is not the main consideration of the equipment, such as some manual operation of simple machinery, can still meet the use of requirements.

4.Movement speed

High-speed movement: Ball Screws can adapt to higher rotational speeds due to the characteristics of rolling friction, and can realize fast linear movement, which is suitable for high-speed automation equipment and machinery requiring fast positioning.
Low-speed movement: Trapezoidal Screws can provide stable transmission in low-speed movement, and because of its simple structure, it is widely used in some low-speed, intermittent movement equipment, such as some manually adjustable valves, small lifting platforms and so on.

5.Self-locking requirements

Self-locking required: Trapezoidal Screws have good self-locking properties, which gives them an advantage in applications where the load needs to be prevented from sliding down on its own or held in position, such as scaffolding lifting systems in building construction, car jacks, and so on.
No self-locking required: Ball Screws are usually not self-locking. If the application does not require self-locking, or if self-locking can be achieved in other ways (e.g., brakes), then the efficient drive characteristics of Ball Screws will be more advantageous.

6.Service life

Long service life requirement: the rolling friction method of Ball Screws makes it less abrasive, and under correct installation and lubrication conditions, it has a longer service life, which is suitable for equipment with long-term operation and high maintenance cost, such as large-scale industrial automation production lines.
General life requirements: trapezoidal screws, although due to sliding friction will produce more wear, but in some of the less frequent use, the working environment is better occasions, can also meet certain service life requirements, such as some small laboratory equipment, home use of simple lifting device.

7.Cost factor

Cost-sensitive: Trapezoidal Screws have a relatively simple manufacturing process and low cost, making them a suitable choice for projects with limited budgets or for applications that are more cost-sensitive.
Cost-insensitive: Ball Screws, despite their higher initial cost, are still the preferred choice in high-performance, high-precision equipment where they are less cost-sensitive due to their ability to increase productivity and reduce long-term operating costs.

8.Working Environment

Harsh environment: In dusty, oily or humid environments, trapezoidal screws are relatively more resistant because of their simple structure, which is not easy to be invaded by impurities. For example, Trapezoidal Screws are more widely used in some outdoor construction machinery and mining equipment.
Clean environment: Ball Screws have higher requirements on the working environment and are more suitable for working in clean and less dusty environments, such as electronic manufacturing workshops, precision instrument production workshops and so on. If they are used in harsh environment, they need to be equipped with good protection devices.

Detailed description of application scenarios for trapezoidal and ball screws

Trapezoidal Screws and Ball Screws have a wide range of applications in different fields due to their different characteristics, and the following are their detailed application scenarios:

Application of Trapezoidal Screws

Machine tools: In the feeding system of some ordinary lathes, milling machines, drilling machines and other machine tools, trapezoidal screws are often used to realize the linear feeding movement of the table or tool. It can withstand large axial force to meet the requirements of the machine tool for feeding accuracy and stability in the cutting process. For example, the feed movement of the large drag plate, medium drag plate and small drag plate of ordinary lathe usually adopts trapezoidal screw drive, which can realize accurate longitudinal and transverse feed and ensure the machining dimensional accuracy of parts.
Pressure machinery: such as punching machines, hydraulic presses, bending machines and other pressure processing equipment, trapezoidal screw is widely used in the transmission of the pressure mechanism. It can convert the rotary motion of the motor into the linear motion of the slide or press head, and complete the process of stamping, extruding, bending and other processes by bearing larger pressure. As the trapezoidal screw has large transmission torque and self-locking performance, it can keep the position stable under pressure to ensure the safety and reliability of the processing process.
Construction Machinery: In some building construction equipment, such as the luffing mechanism of tower cranes and the transmission mechanism of construction elevators, trapezoidal screws are often used for transmission. The luffing mechanism of tower crane drives the trolley on the lifting arm to move along the direction of the lifting arm through the trapezoidal screw to realize the horizontal position adjustment of goods. The self-locking performance of the trapezoidal screw can prevent the trolley from sliding on its own due to gravity in the non-operating state to ensure the safe operation of the crane. The transmission mechanism of the construction hoist uses the trapezoidal screw to transfer the power of the motor to the cage to realize the lifting and lowering movement of the cage, which meets the demand for vertical transportation of personnel and materials in building construction.
Agricultural machinery: for example, the trapezoidal screw may be used in the lifting mechanism of the cutting platform of the harvester and the drive mechanism of the seed dispenser of the planter. The trapezoidal screw in the harvester’s cutting platform lifting mechanism can adjust the position of the cutting platform according to the height of the crop to ensure the harvesting effect. The trapezoidal screw in the seeder drive mechanism of the planter is used to precisely control the rotational speed of the seeder and the amount of seed to be discharged to ensure uniformity and accuracy of seeding.

Application of Ball Screws

CNC machine tools: In all kinds of CNC machine tools, such as machining centers, CNC lathes, CNC milling machines, etc., ball screws are the key components for realizing high-precision feed movements. It can accurately convert the rotary motion of the servo motor into the linear motion of the table or tool to meet the requirements of CNC machine tools for high-speed, high-precision machining. For example, on machining centers, ball screws are used to control the motion of the three coordinate axes (X, Y, Z axes) of the table, and through precise cooperation with the CNC system, they can achieve micron-level or even higher precision positioning and feeding to ensure the dimensional accuracy and surface quality of the machined parts.
Industrial automation equipment: such as robots, automated production lines, semiconductor manufacturing equipment and other fields, ball screws are widely used to realize high-precision linear motion. In the joint drive and arm telescoping mechanism of robots, Ball Screws can provide precise position control and fast response speed, so that the robots can accurately complete a variety of complex movements. In automated production lines, Ball Screws are commonly used in the positioning and sorting mechanisms of conveyor belts, as well as in the precise feeding mechanisms of various machining equipment to improve production efficiency and product quality. In semiconductor manufacturing equipment, such as photolithography machine, etching machine, etc., the high-precision transmission of ballscrews is crucial for the precision positioning and processing in the chip manufacturing process, which is one of the key components to ensure the precision of chip manufacturing.
Aerospace field: Ball screws have important applications in the flight control system of airplanes, the fuel supply system of aviation engines and the transmission mechanism of various on-board equipment. For example, in the flight control system of an aircraft, Ball Screws are used to control the deflection angle of the rudder to realize the attitude control of the aircraft through precise transmission. As the aerospace field requires high reliability, precision and lightweight, ball screws are usually made of high-strength, lightweight materials and undergo strict quality control and surface treatment to meet the working requirements of aerospace equipment under extreme conditions.
Medical Devices: In some high-precision medical devices, such as CT scanners, linear gas pedals, surgical robots, etc., Ball Screws are used to realize the precise movement and positioning of the internal components of the devices. For example, the bed moving mechanism of CT scanner adopts ball screw drive, which can accurately control the position of the patient in the scanning process and ensure the accuracy of the scanning image. The linear gas pedal’s radiation source positioning mechanism and the moving mechanism of the treatment bed are also inseparable from the ball screw, and its high-precision transmission ensures the accuracy and safety of radiation therapy. The joint drive and instrument operation mechanism in surgical robots use ball screws, which can realize precise movement control, help doctors carry out minimally invasive surgery, and improve the precision and success rate of surgery.

Conclusion

Trapezoidal screws and ball screws have shown their strengths in different fields, and their application scenarios are rich and diverse. For manufacturing companies, having advanced and reliable processing equipment is the key to ensuring the quality and production efficiency of lead screws.

As a supplier of specialized in the production of ball screws and trapezoidal screws, we are well aware of the strict requirements of different processes on the equipment. The equipment we provide covers the entire process from raw material processing to finishing and surface treatment. Whether it is ball screw processing equipment that pursues high precision and high efficiency, or trapezoidal screw production equipment that is adapted to large loads and meets basic transmission needs, they are all made of cutting-edge technologies and high-quality materials, with stable performance and excellent durability.

We not only provide you with equipment, but also combine industry experience and your production needs to provide customized solutions to help you improve your competitiveness in the field of lead screw manufacturing and achieve efficient production and quality leap. We look forward to working with you to start a new journey of screw manufacturing together!