Meta-Tools (GregTech 6)

GregTech 6 like many mods, adds several tools for mining or block manipulation. However, GregTech tools are not like the tools from other mods. GregTech tools are known as Meta-Tools, as they are generated as a part of the GregTech material dictionary Meta-Item system. Meta-Tools, in general, are tools that save the particular material(s) used to create them in their NBT, and calculate their traits, i.e. durability, attack damage, and enchantments based on those materials. Each tool has base traits which are combined with the traits of the materials.

Properties
The first notable thing about all Meta-Tools is that they do not follow the conventional item damage system. The tooltip-listed durability of all Meta-Tools is hundreds of times higher than would be expected of normal tools; even the weak Flint Tools have a durability of 6400. There is a purpose to this: GregTech Meta-Tools take damage from breaking blocks proportional to the hardness of the broken block. The damage taken is roughly equal to 100 * Hardness. For tools used in crafting recipes or other non-block breaking actions, in most cases 100 Durability is used.

Trait Combinations
The final...
 * Mining Tier is the sum of the material's tier and the tool's tier (usually 0)
 * Durability is the product of the material's durability and the tool's durability
 * Mining Speed is is the product of the material's speed and the tool's speed
 * Attack damage is the sum of the tool's base damage and the material's base damage
 * Enchant level is the sum of the tool's level and the material's level, for each enchant

Traits
May not be accurate, copied from GT5 pickaxe page