- 800-435-2948
- 800-435-2948
When industrial applications require traversing movement or the ability to carry heavy loads, standard threads often fall short. Acme taps are specifically designed to cut Acme threads, which are trapezoidal in shape and inherently stronger than similarly sized square threads.
Whether you are machining parts for heavy equipment or precision linear motion, understanding the exact specifications, chip load factors, and thread classes of Acme taps is critical for success.
Acme threads allow for reliable rotation and traversing movement on heavy-duty equipment. Because of their broad thread profile, they are commonly found on:
Jacks, Presses, and Valves
Lead Screw Nuts and Linear Actuators
Power Transmission Mechanisms
Because the exactness of Acme thread applications requires close coordination between the tool manufacturer and the user, every tapping job is a minor engineering project of its own.
The standard general-purpose Acme thread provides clearance at all points of contact between internal and external surfaces, ensuring free movement.
While standard Acme taps have a 29° flank angle, Modified Square Threads feature a 10° included flank angle. While they are equivalent to standard Square Threads for practical considerations, they should not be used in applications where a standard Acme thread can serve the same purpose.
For metric applications requiring similar traversing capabilities, Trapezoidal Thread Taps serve as the metric equivalent to Acme taps, creating the broad threads necessary for metric lead screw nuts and linear actuators.
One of the most significant challenges when using an Acme tap is chip management. The block-like profile of an Acme thread requires a massive amount of material to be cut and removed, making chip load a major factor that must be strictly controlled.
To manage this material removal, manufacturers typically utilize two main tapping strategies:
1. Standard Tap Sets: These sets typically include one or two roughing taps and a final finishing tap.
2. Tandem Acme Taps: Tandem taps feature a roughing section built directly ahead of the finishing section on the same tap body. A single-pass tandem Acme thread tap can produce complete threads in a single pass without the need for a leadscrew.
Acme taps are commonly manufactured from High Speed Steel (HSS). They are available in a massive range of sizes (from 1/4″ to over 1-1/2″) and pitch variations (such as 4 to 12 threads per inch).
Additionally, configurations can be modified based on directional needs:
Right-Hand Taps: The standard direction for most industrial Acme threads.
Left-Hand Taps: Used to create left-hand Acme fasteners, which are essential for securing counter-clockwise rotating parts.
Multi-Lead Taps: Can be manufactured as single-lead or multi-lead depending on the speed of motion required.
Acme threads are trapezoidal in shape and feature a 29° included flank angle, making them stronger and easier to machine than standard square threads. Modified Square Threads, by contrast, have a 10° included flank angle.
A Tandem Acme Tap is designed with both a roughing and finishing section on a single tool body. This allows the tool to cut a complete Acme thread in a single pass, completely eliminating the need for a leadscrew.
Because Acme threads require the removal of a large volume of material, chip load is controlled by dividing the cut. This is done either by using a set of multiple taps (one or two roughers followed by a finisher) or by using a single-pass tandem tap.
These are Class of Fit symbols for American Standard General Purpose Acme Threads. The numbers dictate the specific tolerances and the amount of backlash allowed between the mating parts.
Yes, left-hand Acme thread taps are specifically manufactured to thread holes for left-hand fasteners that secure counter-clockwise rotating parts.