GUITAR STRINGS NICKEL VS STAINLESS STEEL
As far as material is concerned, we can divide strings into two main categories: nickel strings and stainless steel strings.
The majority of so-called nickel strings are actually made of steel and coated with an 8% nickel wash that acts as protection and softens the touch.
Steel strings are made from a highly magnetic alloy and usually produce a brighter sound and a rougher feel under the fingers. Due to the greater brilliance, when used just as frequently, they can be more long-lasting than nickel ones and will tend to highlight any imperfections of the fretboard (buzzing, etc..).
The sound of nickel strings is normally associated with a less brilliant and more full-bodied sound. The touch is more smooth to feel.
Being brighter stainless steel strings are recommended for modern rock and metal and slap on the bass while nickel wound strings are recommended for those who are looking for a more vintage "hot" tone. Steel strings are more suitable for slapping and funky and modern rock sounds, while nickel strings are better-suited to classic rock or for more versatile use.