Choosing between thread rolling and thread grinding can be difficult. After all, each process benefits acme screw applications in different ways. If you’re struggling to choose a thread forming process for your acme thread design, the following considerations can help you decide.
What is Thread Rolling?
Thread rolling is the process of forming screw threads by rotating a hardened steel die against the surface of a cylindrical blank. The blank rolls against the threads of the in-feeding dies, displacing materials to form the root of the thread.
This process produces strong acme precision threaded rods, perfect for applications that need greater strength and fatigue resistance. Rather than cutting against the natural grain of the metal, thread rolling reforms and hardens these structures. There are no sharp corners in the thread roots or tool marks on the thread flanks. They also have a higher resistance to stripping.
Thread Rolling Advantages
Thread rolling offers several advantages over other thread forming methods.
Thread rolling is often the most cost-effective method for standard acme thread design. At PST, we have an extensive inventory of thread rolling dies which helps guarantee a quick turnaround.
Rolled material is stronger than ground material because the rolling process does not chip or remove any of the raw materials.
Watch our video below to learn more about acme thread rolling.
What is Thread Grinding?
Thread grinding utilizes a CNC machine with an abrasive grinding wheel to form threads. This process produces tight-tolerance acme precision threaded rods which are perfect for applications with unique part geometry or where a custom fit is required. Unlike thread rolling, no special tooling is required, making thread grinding ideal for low-quality or prototype manufacturing lots.
Thread Grinding Advantages
Precision thread grinding offers several advantages to thread rolling.
Thread grinding can be used to create complex and highly specific screw thread designs. For this reason, thread grinding is often the ideal process to meet custom backlash requirements.
The thread grinding process allows threads to be cut into high hardness materials, as some materials are too hard or brittle to be rolled. Thread grinding is also the only process that allows threads to be cut after the material has been heat treated.
For example, an existing PST customer came to us with an application used in a flat actuator of a single engine aircraft. Cost and weight were the driving factors for this project, so an acme screw assembly was used instead of a ball screw assembly.
The requirements for this acme screw thread were strict, as the acme screw and acme nut had to be custom matched sets. Thread grinding was used to create a highly efficient assembly with minimal backlash. Our engineers also created a custom acme thread design that met the requirements for the aircraft.
Once the design was finalized, prototypes were designed and manufactured for testing. This project is still in development, and the customer is performing tests to prove out their design. However, this design is flexible. Once these tests are complete, if there are changes to be made, our engineers will work with the customer to move the project in the right direction.
Watch our video below to learn more about acme thread grinding.
Which method is best for you?
Whether utilizing thread rolling or thread grinding, choosing an acme threaded rod manufacturer that offers flexibility is key.
At PST, our ability to deliver quality custom projects is what sets us apart. You put it to the test, and if something needs to be adapted, we’ll make it work.
Are you looking for a partner to custom design an acme screw for your application? Our team of experts are ready to help. Contact us today.