# Autodesk Inventor/Part Creation
## Part Creation

Part creation is the process of making a 3D model that can later be used to generate Drawings, or as part of an Assembly.
Parts can be created on their own, or while editing an Assembly.
To make a Part, one can either build it from scratch, or build it based on existing parts by using the Derived Part function. The Derived Part function imports the 3D model of another part (the parent) and allows the new part (the child) to use features of this part in the creation process of the new part. The child will always be linked to the parent. So if the parent is altered, then the child will adopt the changes as well.
The concept of using Derived Parts is useful for many applications. When building Parts that must mate with existing Parts, the mating surface of the new Part can be Derived from the old Part.
An example of this would be a bolted flange that attaches to the side of a tank the designer is currently working on. Or another case could be if the designer is building some tooling like a mold to cast a part that was previously modeled. The mold could have all of its casting surfaces derived from the Part Model. This is extremely useful if the Part Model is complex, or still in development.
Using Derived Parts can also be used to show a part though various stages of manufacturing. A part that is created from a casting can be first created to represent its as cast state. Then a Derived Part can be created from the first to show the finished product after machining operations.

## Types of Parts

There are three main types of Parts.
* Standard Parts
* Sheet Metal Parts
* iParts (sometimes called Factories)
Standard Parts are plain 3D models. All Inventor generated parts share the features available to Standard Parts.
Sheet Metal Parts contain additional design tools specially suited to making components made from thin, ductile material. Since oftentimes these types of parts are bent, Inventor contains several tools to aid the designer. While creating a Sheet Metal Part, the designer has the option to view a 'Flat Layout' of the current model. This shows the designer how his/her material would have to be cut in order produce the part. If the designer assigned the proper material to the model, then Inventor will modify the Flat Layout to reflect the proper bend allowances.
iParts is a single 3D model that has variables can be set when inserting the iPart into an Assembly which allows the iPart to become one of an entire family of parts. An example of this would be a screw. As you know there are probably thousands of different sizes of screws available to make the products we use every day. But the vast majority of these screws are basically the same with the exception of their diameter, length, and thread pitch. With an iPart, the designer can easily program the hundreds of combinations of these variables into a single model. Then when the designer needs any one of these screws, she can simply insert the iPart, select the diameter, length, and thread pitch, and the new screw is ready to be used.
Any part can be converted into an iParts. Thus even a Sheet Metal Part can be an iPart. The designer is not limited to choosing to make an iPart over any other type of part.