Ningbo Weifeng Machinery Co., Ltd. [China]

1:Smooth 2:quiet 3:and low maintenance 5:Precise

A leadscrew nut and screw mate with rubbing surfaces, and consequently they have a relatively high friction and stiction compared to mechanical parts which mate with rolling surfaces and bearings. Leadscrew efficiency is typically between 25 and 70%, with higher pitch screws tending to be more efficient. A higher performing but more expensive alternative is the ball screw. The high internal friction means that leadscrew systems are not usually capable of continuous operation at high speed, as they will overheat. Due to inherently high stiction, the typical screw is self-locking (i.e. when stopped, a linear force on the nut will not apply a torque to the screw) and are often used in applications where backdriving is unacceptable, like holding vertical loads or in hand cranked machine tools. Leadscrews are typically used well greased, but, with an appropriate nut, they may be run dry with somewhat higher friction. There is often a choice of nuts, and manufacturers will specify screw and nut combination as a set. The mechanical advantage of a leadscrew is determined by the screw pitch and lead. For multi-start screws the mechanical advantage is lower, but the traveling speed is higher.[7] Backlash can be reduced with the use of a second nut, or a tensioning spring, to create a static loading force known as preload; alternately, the nut can be cut across its diameter and preloaded by clamping that cut back together. A leadscrew with a sufficiently high helix angle can back drive: forces on the nut applied parallel to such a leadscrew will cause the leadscrew, if it is not otherwise held in place, to rotate. Such a tendency to backdrive depends on the thread helix angle, coefficient of friction of the interface of the components (screw/nut) and the included angle of the thread form. In general, a steel acme thread and bronze nut will back drive when the helix angle of the thread is greater than 20°.

0.132" (3.3mm) Lead Screw