Ball Screws & Lead Screws
Rolled and ground ball screws, ACME lead screws and nuts.
Also searched as: ballscrewacme screwlead screwsfu1605trapezoidal screw
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ACME Plain Finish Heavy Hex Nut
Dia/Thread Size: 3/4"-6
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ACME Plain Finish Heavy Hex Nut
Dia/Thread Size: 1-1/8"-5
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About ball screws & lead screws
Ball screws and lead screws convert rotary motion into linear motion, or vice-versa, with high precision and efficiency. Ball screws utilize recirculating ball bearings between the screw shaft and the nut, providing low friction, high efficiency (typically >90%), and minimal backlash. They are available in rolled and ground variants; ground ball screws offer superior precision and smoother operation, often specified for demanding applications. Common types include single nut, double nut, and preloaded nuts to eliminate backlash. Key selection parameters include nominal diameter, lead (pitch), screw length, accuracy grade (e.g., C0 to C10 for ball screws), dynamic and static load ratings (Ca, Coa), and critical speed. Lead screws, including ACME and trapezoidal forms, rely on sliding friction between the nut and screw. While less efficient (typically 20-80%) and prone to wear, they are self-locking in many configurations and more cost-effective. ACME screws conform to ANSI/ASME B1.5 standards, often with 29-degree thread angles. Materials for screws are typically alloy steels like 1045 or 4140, often induction hardened and chrome plated for corrosion resistance. Nuts are commonly bronze, plastic (e.g., Delrin), or steel, depending on load and wear requirements.
How to choose
Selecting the appropriate ball or lead screw begins with defining the application's force and speed requirements. First, determine the maximum axial load and the required travel distance and speed; this dictates the screw's diameter and lead. Next, consider the required positioning accuracy and repeatability: ground ball screws offer the highest precision, while rolled ball screws provide a balance of performance and cost, and lead screws are suitable for less demanding applications. Evaluate the duty cycle and desired lifespan, as this impacts the choice between low-friction ball screws and higher-wear lead screws. Finally, assess environmental factors such as temperature, contamination, and lubrication needs, which influence material selection and protective coatings. Consider backlash requirements; preloaded ball nuts eliminate backlash, while lead screws may offer inherent self-locking properties.