APT Full Form is Automatically Programmed Tooling. APT is a computer programming language useful for generating instructions for devices performing mechanical operations. These mechanical machines are computer assisted where the instructions are generated from the computers. APT was developed at MIT in 1956-59 and Reynolds George is believed to be the father of APT. The APT program consists of the following four: Geometry, Motion commands, Post processor statements (speed tolerance values) and auxiliary statements.
In the geometry, the basic dimensions of the object like the lines, surface, points for the object to be worked upon (say cutting) are clearly defined. The whole object is divided into a 3-D mesh consisting of small differential elements which can be integrated upon mathematically. These complex integration functions form the basis for the object definition. The geometry information gives all the information in terms of where an object is to be worked upon and what kind of pressure to be applied to a particular region of the object.
In motion commands, the point to point motions, contour motions, and other motion programs are defined for the cutting tool to move and find the exact location to work upon. Auxiliary statements are used to identify the part program, specify which post processor to use, insert remarks into the program, etc. The APT provides a technique that offers repeatability and reproducibility with precision and in a time defined orderly manner.
This is thus an important tool for development of mass production. The APT forms the basis of the newly developed technique 3-D printing which is believed to be the next big revolution set to change the manufacturing industry. Even the industrial robots which excel at performing a specific but highly complex mechanical job use APT.