Precision Ground Ballscrews over Rolled Ballscrews

Haas factory Ballscrews are made by some of the same manufacturers who supplies screws for box way Fadal machines. They are precision ground screws rather than rolled screws, which are more expensive to make, last longer, and are more accurately made and repeatable.

The staff at Steinmeyer (http://www.steinmeyer.com/) as well as most others can explain in detail why precision ground ballscrews are preferable to rolled screws for most CNC mills and lathes machines and other precision applications. First, the accuracy of a rolled screw can be masked by a proper lead error even though other issues, like eccentric journals, will later become apparent and shorten the life of the screw. Ground ballscrews, on the other hand, have a longer life and better accuracy due to superior grind quality and lubrication methods. They have long been the preferred choice for precise applications.

The main reason that rolled screws lack the accuracy and durability of ground screws is due to how they are made. Rolled screws are made in a one-step process that does not allow for alterations or corrections once the threading is complete. To put every step into this one process, the metal is put under high stress, often lengthening the metal in unpredictable ways. In contrast, ground ballscrews are made in a step-by-step process with multiple quality control processes. Ground screws are always kept centered while slowly formed over many steps, allowing the manufacturer to periodically check and fix any eccentricities during the process.

The high stress that rolled screws are placed under also makes them less durable. In contrast, the steps when making a ground screw include several processes for relieving pressure from the metal. By breaking the process into smaller steps while keeping the center of the screw consistent, a ground screw is put under less stress and reproduced much more consistently. This step-by-step process also makes it easier to make a custom screw that is just as high-quality.

We offer a full 1-year warranty on all Ballscrews, regardless of the installer, and you will be quite pleased with the added performance. Put some “Plus” in your Haas home CNC machine with HaasPlus.com!