A Part is the form an item is in, for example a gear or an ore.

It might be required for you to import the package if you encounter any issues, so better be safe than sorry and add the import.
import mods.contenttweaker.Part;

You can either retrieve an existing Part using the MaterialSystem or create an entirely new one using the Part Builder

Following types are pre-registered (Headlines are the Part types):

Items:

Link to undefined

• Beam
• Bolt
• Casing
• Clump
• Crystal Crystal
• Crushed Ore (crushed_ore)
• Dense Plate (dense_plate)
• Dirty Dust (dirty_dust)
• Dust
• Gear
• Ingot
• Nugget
• Plate
• Rod
• Shard

Blocks:

Link to undefined

• Block

Ores:

Link to undefined

• Ore
• Dense Ore (dense_ore)
• Poor Ore(poor_ore)

Fluids:

Link to undefined

• Molten

Armor:

Link to undefined

• Armor

Minecart

Link to undefined

• Minecart

You can retrieve the following information from a Part:

ZenMethod	Return Type
ZenMethod hasOverlay()	Return Type boolean
ZenMethod getName()	Return Type string
ZenMethod getUnlocalizedName()	Return Type string
ZenMethod getShortUnlocalizedName()	Return Type string
ZenMethod getPartType()	Return Type PartType
ZenMethod getPartTypeName()	Return Type string
ZenMethod getOreDictPrefix()	Return Type string
ZenMethod getData()	Return Type List<IPartDataPiece>

You can use this to register one or several Materials to this part

ZenScript
 Copy
part.registerToMaterial(Material material);
part.registerToMaterials(Material[] materials);

The function will either return a single MaterialPart object or a List of them, depending on whether you registered one or multiple materials at once.