Steel Works
Steel Works follows 
Smithy II in the metallurgy technology branch.
Prerequisite
Section titled “Prerequisite”Smithy II is the prerequisite.
Technology point cost
Section titled “Technology point cost”The definition lists a cost of 175 red and 20 blue technology points, with no green point cost.
Unlocks
Section titled “Unlocks”
The technology unlock list contains Engineering Kit, Supply: Steel Tools and Smithy: Grindstone.