Stainless Steel has large advantages against the normal steel especially in coastal areas. Salt water will roughen the normal steel plating which will dull and rust the chain—this cannot happen with stainless steel. Additionally you have the advantage of a higher security and a long lifespan.
Matte Chrome is our attractive and robust surface called Satin Chrome. The chains are as strong as you know the sprenger quality from the normal chrome plating. The plating neither becomes shiny nor does it come off.
Curogan is a copper-tin-alloy with a high copper portion and additives which make the material strong - but without the nickel which can cause allergic reactions for some dogs. Therefore these chains avoid discoloration of fair haired dogs.
Brass is softer than steel. Variably progressing abrasion inside the chain links depending on the power of the dog. A brass chain has to be inspected regularly and replaced early enough.