What are Lead Screws?

While there are many ways to join objects together, whether that be through crimping, welding, soldering, gluing, and more, fasteners are the perfect solution for non-permanent joints. A type of hardware device used to join or affix two or more things together, fasteners are typically made from stainless steel, carbon steel, or alloy steel that allows for prolonged part reliability. Available with special coatings or plating to further improve a fastener's resistance to corrosion and weather phenomena, fastener screws are constructed with various characteristics to suit application methods within different materials. However, unlike traditional screws that hold items in place, lead screws are manufactured to provide continual motion within an assembly. Primarily implemented within an apparatus to facilitate linear motion, lead screws are classified by the shape of their threads and are available in square thread, trapezoidal (ACME) thread, and buttress thread variations.

As lead screws are heavily dependent on their threading to produce a suitable amount of friction against connections, it is optimal for such components to only be used when shaped with square, trapezoidal, or buttress threads. Best for transmitting power in any direction, square threads are known for their prolonged reliability by mitigating radial and bursting pressure often imposed on a nut. Alternatively, for the sole purpose of power delivery, lead screws with trapezoidal threads are equipped with thicker roots to supply a network with higher load-carrying capacities. Meanwhile, buttress threads enveloping a shaft can only be used to carry large loads in one direction.

Often referred to as power screws or translation screws, lead screws are manufactured in the same fashion as other thread forms, but are not meant to join parts as a regular screw would. Rather, lead screws serve as a linkage component in machinery, translating turning motion into linear motion when a system is activated. Predominantly used within electric linear actuators, lead screws are also commonly applied in linear actuators, machine tools, vices, presses, and jacks. Inefficient for high power applications, lead screws are advisable for low power actuators and positioner devices where large areas of sliding contacts are present.

Paired in conjunction with a split nut or half nut, nuts should always be applied to alleviate excess friction causing wear to a lead screw's threading. If wear is present along a lead screw’s shaft, a split nut may also be used to compensate for worn threading by compressing parts of the nut. This allows the nut to firmly grasp threading along the screw for support. Capable of disengaging from a lead screw's threads, applied split nuts can also move independently of a screw's rotation, shifting axially along the shaft when needed. Generating sliding friction as they move, rotational movement generated by an assembly used to drive a lead screw will cause the apparatus to turn, subsequently adjusting the nut along the screw shaft in a linear motion. While a nut applied for lead screw applications may be constructed from various materials like plastic and other similar composites, they are often made from metal for demanding industrial applications.

As time is of the essence when you require parts critical for your operations, we invite you to browse our inventory for numerous lead screws ready for system implementation. Whether you require a specific power screw, split nut, actuator component, or any other fasteners , NSN Sphere is here to streamline and expedite any one of your orders for immediate procurement. Due to our quality control and export compliance, we operate with AS9120B, ISO 9001:2015, and FAA AC 00-56B certification and accreditation, alongside our NO CHINA sourcing pledge. If you would like to request a quote for your comparisons, you can submit an RFQ form as provided on our website. Upon receipt, a dedicated account manager will quickly review and respond with a personalized solution to your needs in just 15 minutes or less, 24/7x365.

About Author - Charles Howard

Charles Howard 29 Blogs

Charles Howard is a passionate aviation enthusiast with over 15 years of experience in the industry. Holding a degree in Aerospace Engineering, Charles has worked with some of the top aerospace companies and has been involved in various groundbreaking projects that have shaped modern aviation.

Currently Charles is leading the content marketing team at NSN Sphere. Charles's passion for writing is matched only by his commitment to delivering value to his readers. His blogs are known for their clarity, creativity, and ability to distill complex topics into easily digestible and enjoyable reads.