A Closer Look at Twin-Lead Acme Screw Assemblies

Christopher Nook by Christopher Nook

If you are reading this, you probably know a thing or two about Acme lead screws and how they are fast becoming the preferred choice among design engineers when working with certain types of linear motion applications. One of the reasons for this, as we've covered in a previous article, is the fact that Acme lead screws come in "many different flavors", meaning that you'll be hard-pressed not to find one that fits your application.

If you are reading this, you probably know a thing or two about Acme lead screws and how they are fast becoming the preferred choice among design engineers when working with certain types of linear motion applications. One of the reasons for this, as we've covered in a previous article, is the fact that Acme lead screws come in "many different flavors", meaning that you'll be hard-pressed not to find one that fits your application. From various thread forms to a multitude of material choices, from design freedom to coating and lubrication options (or lack thereof), there truly is an Acme lead screw for just about any linear motion application.

Today, we're going to take a close look at twin-lead screws and what they have to offer.

Specifically, as its name somewhat implies, a twin lead screw is one that offers dual opposing motion while using a single drive system. That's right - simultaneous right and left movement from a  center line, but on a single drive system or motor. It's a one-piece screw that is designed for high performance applications. The one-piece format offers several advantages over other types of screws. For instance, it allows for easy, convenient installation, while eliminating the alignment problems that are often associated with segmented versions.

Twin-lead Acme screws are typically made from alloy steel and black oxidized for further protection. What's more is that they can be easily assembled with the various nuts, flanges and EZZE-MOUNT bearing supports, depending on the intended application, to offer enhanced support in a cost-effective manner.

So just what types of applications are twin-lead Acme screws ideal for? They're ideal for high performance applications with low duty cycles or manual drive operation. Some popular applications include:

  • Molding machines
  • Packaging equipment
  • Food processing machinery
  • Robotics
  • Material handling applications
  • Tire manufacturing
  • Other assembly applications

Fitting the theme of Acme lead screws themselves, twin-lead screws come in various different flavors as well. When it comes to the end product, they are available with or without machined ends and can be cut to a custom length. They are also available with both bronze and plastic nuts.

Perhaps the most popular type of twin-lead Acme screws are those that are thread rolled. Thread rolled twin-lead screws typically offer lead accuracy of 0.0002-0.0003 inches. Rolled twin-leads are also said to be much more economical than ground screws.

Like standard Acme lead screws, twin-lead screws offer many of the same benefits. For instance, as we already covered, they're very economical and cost-effective, meaning that you won't be breaking the bank if your application requires a twin-lead assembly. This cost savings helps your bottom line and can also be passed on to the end user. As we already hinted, twin-lead screws are also very versatile - available to be configured with a variety of nuts, flanges and end bearings supports. And, as is a theme with Acme lead screws, they're able to be integrated into the envelope of the application, meaning that you won't have to design around the screw assembly, but rather the screw assembly can be integrated without hassle into the existing design. It's true design flexibility.

Small Helix twin-lead screw assembly

Twin-lead Acme lead screw assemblies aren't used as often as traditional screw assemblies due to the requirements of the application but for the likes of molding equipment, packaging equipment, food processing machinery, robotics, material handling - and others - they make sense and allow such applications to operate to their full potential without compromise.
To learn more about twin-lead screws and the other products that we offer, feel free to contact one of our experts by calling 855-435-4958 or visit our website. We've also created a two-part lead screw terminology guide that you may find useful.  Click the link below to download a copy.

Download your engineer's guide: lead screw sizes in inch and metric.