Silicon bronze fasteners are excellent for use in many marine and commercial applications which was made from copper with silicon added for strength.Silicon bronze is known as a high-strength alloy,having a several important factors including high conductivity,excellent corrosion resistant to sea water,gases,sewage and atmospheric conditions. Silicon bronze nut(C65100,C65500) was manufactured according to ANSI,DIN,etc. Hexagon heavy nut,finished jam hex nut,full hex nut,machine screw nut,etc. Internal diameter of of Nuts:#8-1 1/2"(M4-M36) Threads:UNC/UNF,BS threads,Metric threads,other threads according custom design. packing:polybag and carton.