Before you understand whether you need an ACME thread or not, you need to know a little bit about the history of the threads. How did these come into the picture, and what is their role? What makes them more efficient than the other types of threads? Do you want to know the answers to the above-mentioned questions? Then continue reading all the way to the end. 

It wasn't until the late 1800s that ACME thread tap was introduced as an improvement over square threads. Motion transfer and heavy loads necessitated the use of square threads. However, the available cutter technology made it difficult to produce square threads. The 90-degree angle of the flank of the square shape made it inherently weak at the base of the thread, making it prone to breakage. The thread's base was strengthened by widening it by 29 degrees by changing the included angle. ACME diameters and pitches were standardized over time, all in Imperial Inches in diameter and Threads-per-Inch units of description.

Lead screw shafts in various assemblies benefit greatly from ACME and Buttress threads. Specifically for load-bearing or precision-assembly movements, Lead screw shafts are visible in some equipment, but the majority of them remain unseen. As an example, lead screw mechanisms can be used to lift pallets, label machines, medical diagnostics, personal mobility, off-road vehicles, and machine tools, all of which require load-bearing or precise movement.

Lead screws typically require special thread forms because of their high strength and precision requirements. For lead screws, the most common trapezoidal thread form is ACME. Despite their efficiency, square threads are still difficult to manufacture. It is less expensive to produce an ACME 29° angle in both external and internal threads because it is simpler to do so. Multiple starting threads, left-hand threads, and self-centering threads can all be used to make them.

Many shops have a wide variety of ACME thread taps in standard sizes, as well as a wide variety of special purpose taps, typically with a coarse pitch. Unipass ACME combines both a roughing and finishing section into one tool, making it one of our most popular designs.

To withstand extremely high axial thrust, the buttress thread form was created. The weight-bearing surface has a 7° angle, while the trailing flank has a 45° angle, resulting in a form that has good shear strength.

Trapezoidal thread vs. ACME thread. Are there any better choices here?

When rotated, both thread types produce linear motion under heavy load. Table lifts, clamps, and vises, valve stems, jack stands, and lead screws for linear actuation on CNC machines are all examples of common applications.

Generally, ACME threads are preferred because of their widespread use and acceptance as a standard, but both are excellent choices. Choosing a material depends largely on where the finished product is going to be used and who is going to use it. The thread type may seem insignificant to the consumer, but it matters a great deal to the manufacturer.