Copper Tube

Copper Tube is created and mostly used by engineers.

Source
Copper Tube is made by engineers with a skill of 50.

The schematic is learned from the engineering trainer.

It is also dropped by Harvest Golems.

Copper Tube as an Ingredient
Copper Tube is used in the following recipes:

Engineering

 * Rough Boomstick
 * Deadly Blunderbuss
 * Crude Scope