Compression-Spring Iran Import and Export Companies

I want to make a factory to produce airspring in my country, I need used machinery ( not old) and your experience about it, could you please give us advice?

We are negotiating reliable and experienced manufacturers of compression springs producing springs capable of bearing forces from few hundred Kilograms to about 70 or 80 tones with accurate spring of limited tolerances ( say 2 to 3 percent ) .