What is brass??
Brass is beautiful metallic luster and excellent  corrosion resistance .
Because it has excellent conductivity, can be used for  electrical is easy through.
It also will be able to secure the screws.
Rust, conductive, decoration, you want to use.  

High quality and high precision Brass Hexagonal nuts  

CHIbaseIRA CO LTD History 

(Japanese manga veiw)

http://www.chibaseira.co.jp/book_2/_SWF_Window.html

 CHIbaseIRA Home page

http://www.chibaseira.co.jp/english.html