Once you are an experienced dwarf, the importance of different metals is well known. You know that steel is the best common metal for weapons and armor. You know that nickel is pointless. This mod allows you to generate a whole new set of metals with randomized properties to explore.
Hit "Make Metals" until you find a set that you like. Then press "Download Raw Files". Deposit the resultant text files into your /raw/objects folder in Dwarf Fortress. One of the files generated is called mod_info.txt and contains an overview of the generated metals and ores. It does not need to be placed in your df folder. Be sure to save a copy of the vanilla files if you want to restore them later.
A pure metal that can be made from a single ingredient. Examples include copper, iron, and lead.
An alloy is a metal made from two or more other metals. These include bronze and pewter.
An advanced metal is made made by combining a metal with a non-metal. In vanilla DF the only advanced metal is steel. Other metals serve as the precursor to advanced metals but are not usable (e.g. pig iron). Advanced metals can require up to six production steps. Generated advanced metals receive a bonus to their strength based on the rarity of their non-metal ingredients and the length of their production chain.
Strength is an approximation of the material properties of the metal. Higher strength metals will generally make better weapons and armor. Vanilla strengths range from 0.07 (lead) to 1.21 (copper) to 3.96 (steel). Generated metals with a strength above 1 can be used for weapons/armor and those above 1.7 can even be used for anvils.
Adamantine holds a unique place in DF. I didn't want to change that.
The basic material properties (Young's modulus, density, etc.) are pulled from a distribution of typical values for metals.
This seems to be an issue with TWBT. It can be avoided by reducing the size of your DF window before embarking. The window can be expanded once you have embarked.
* Intermediate metal that cannot be used to make objects (like pig iron).