Steel Billet

A strong metal alloy composed of iron and carbon.

Steel Billet is used in the following crafting recipes:

Back Brace	Muscles + 2.0
Beetle Miner	Vehicle capable of mining surface resources
D.O.G.E.	The Distance Operated Geo Explorer is a surveillance vehicle designed for remote exploration and biome scanning.
Fasteners	Various screws, nuts and bolts.
Improved Engine	Movement Speed × 150%
Improved Pump Motor	Water Output × 120%
Repair Kit	A more efficient repair kit used to repair machinery.
Resource Transport	A basic resource transport vehicle. Will automatically collect resources from closest building(s), but can also be assigned to specific buildings.
Rover	Passenger vehicle that will allow colonists to investigate points of interest on the surface.
Sturdy Frame	Muscles + 2.0

And to construct the following structures:

Algae Farm	A sophisticated way to grow beneficial sludge.
Aquarium	A place for growing and harvesting fish.
Clone Chamber	No longer are we required to toil in the unpredictable task of normal procreation. The clone chamber allows us to create new colonists.
Elevator	Connects the underground facility to the surface.
Fish Tank	A decorative object to keep colonists happy. Don't tap the glass.
Glowing Spheres	A decorative stack of illuminated balls.
Launch Platform	Satellite delivery rockets can be launched from here.
Map Table	Unlocks the ability to monitor surface operations including expeditions.
Medi-Bed	Heals the sick as long as there is a good doctor.
Memory Transfer Station	Used to transfer job skills from one colonist to another.
Mining Platform	Placed on a surface resource to harvest sub-surface and deep resources.
O2 Generator	In order to grow our population we'll need more of these. Increases colonist cap.
Resource Depot	Allows access to the shipping & recieving inventories by vehicles
Resource Scanner	A surveyor will use this station to scan for hidden sub-surface resources on explored planet tiles.
Robot Assembler	Station for constructing robots.
Solar Panels	Generates power from solar energy. Hot and dry biomes increase performance.
Trade Platform	A place for passing space ships to stop by so you can buy and sell goods.
Vehicle Bay	Constructs vehicles to explore and exploit the planet surface.
Wind Turbine	Generates power from wind. Higher elevations will increase performance.