Why don’t pullers use acme thread screws?

[Firebrick43]

Acme

5/8 is 8 TPI

3/4 is 6 TPI

They can be finer but they won’t be acme standard threads.

Acme threads deliver lower mechanical efficiency than standard V-threads due to higher friction from their trapezoidal geometry, but they excel at handling heavy axial loads and power transmission. [1, 2, 3]

Mechanical Advantage and Efficiency

• • Standard V-threads (60-degree angle): Provide higher linear force per unit of torque and better mechanical efficiency in standard fasteners because of a steeper helix angle and tighter fit. However, they are prone to stripping under heavy dynamic loads. [1, 2]
  • Acme threads (29-degree trapezoidal angle): Feature increased friction caused by the wedging action of their sloped flank sides. This reduces their mechanical efficiency (typically around 40–50% even when lubricated) compared to ideal square or standard tightening threads

Is this an AI quote????

Did you read the links? At least link 1 and link 2 contradict the statement proceeding the links entirely. I don't do Instagram so on link 3.

Here is a direct quote from link 1...

"1. Flank Angle and Friction Dynamics​

The most visually apparent difference between ACME thread and normal thread is the flank angle—29 degrees versus 60 degrees. The steep 60-degree angle of a normal thread acts like a wedge. As you tighten a bolt, the radial force pushes outward, creating high friction. This is perfect for a fastener that you want to remain permanently fixed. However, if you try to use a 60-degree thread to continuously move a heavy load (like a machine table), the wedging action causes severe friction, rapid heat generation, and accelerated mechanical wear.

The 29-degree angle of the ACME thread drastically reduces this radial wedging force. When torque is applied to turn an ACME lead screw, the force is directed much more linearly along the axis of the screw. This fundamental difference between ACME thread and normal thread physics allows the ACME mechanism to move heavy loads with significantly less rotational effort and far less wear on the mating nut."



The video in link 2 even gives the math to calculate the thread efficient in relation to its angle. I think why AI is confused is that its comparing square threads to acme thread. In that case because of the angle acme threads are less efficient than square threads. But the same math makes 60 degree threads 50 percent less efficient than acme threads.

More proof that AI is ****.