# What pitch is acme thread?

## What pitch is acme thread?

American National Thread ANSI/ACME B1. 5-1977

Nominal Diameter Major Diameter Inch Pitch mm
1/2″ – 10 ACME 0.500 2.540
5/8″ – 8 ACME 0.625 3.175
3/4″ – 6 ACME 0.750 4.233
7/8″ – 6 ACME 0.875 4.233

All three varieties of acme threads use a 29-degree angle, which makes it broader, stronger and more square than standard V-shaped threads. They are often used for jack screws, lead screws, CNC systems and many other applications.

What is a 2G acme thread?

Acme Thread Designations For example, 1/4-16 acme -2G is a screw having a 1/4 inch diameter and 16 threads per inch. Its class is 2G and it is a conventional right-handed screw.

Why is it called an ACME thread?

It provided a screw thread which was easier to machine and had optimal properties for power transmission. Thus, the term ACME was applied to the 29° included angle screw thread form. The word ACME as defined by Merriam-Webster as the peak, the one that represents perfection of the thing expressed.

Acme thread is used for power transmission. It has higher load carrying capacity in comparison to square threads, because of larger root thickness. Acme threads are manufactured on a milling machine using a multi-point cutting tool and are therefore economical to cut.

ACME thread: It has an included angle of 29°. These are used in lathe lead screws. It is stronger than square threads.

How is ACME thread pitch calculated?

Parameter Equation
Basic Pitch Diameter (D2) D2=D−0.5P
Basic Minor Diameter (D1) D1=D−P
Thickness at Pitch Line (t) t=P2
Basic Height of Thread (h) h=P2

A screw thread whose lead or the distance traveled when the screw rotates once, is equal to the pitch (P) and is called a single start thread. A screw thread whose lead (L) is equal to twice the pitch is called a two start or double thread.

## Are Acme threads self locking?

Unlike other types of lead screws, Acme screws are self-locking when the selected efficiency is below 35 percent.