Brass ←
Brass is an orange-gold metal. It is really soft and easy to machine.
Brass has self-lubricating properties which leads to it being used for mechanical components that need to move for a long time:
Bushings, Glide Surfaces, Gears, etc.
It's golden color also lends itself well for decorative elements like knobs and handles.
Notes
To achieve the desired low-friction porperties brass parts need to be really clean and may need a bit of additional lubrication. I recommend either sewing machine oil or a thin synthetic grease (e.g. Super Lube)
