Moving on from fret size considerations, now we’ll take a look at the materials fret wire is typically made from. While some companies like Rickenbacker use a proprietary fret material, what follows is what you'll typically encounter.
Good, old-fashioned brass was—and still is—used for frets. Many vintage instruments will come with brass frets and, even today makers like Warwick sometimes use brass frets in their instruments.
Brass is an alloy of copper and zinc and, as you’d expect, these frets have a ‘brassy’ colour. Brass frets are not the hardest in the world and do tend to wear more quickly than other wires.
Nickel Silver Frets
The first sentence of every thing ever written about nickel silver will always remind you that it actually contains no silver. Nickel silver is a copper alloy—effectively it’s brass (copper and zinc) with nickel added for hardness. This nickel is sufficient to shift the brass colour towards the silver coloured frets we’re familiar with. The amount of nickel determines how hard the fret will be. Most guitars are fitted with 18% nickel frets although it’s possible to get 12% nickel wire too. The latter is used relatively rarely.
Nickel silver frets are so ubiquitous that I probably don’t need to say much about them. Pick up your guitar or bass and that’s almost certainly what’s installed in it.
Stainless Steel Frets
Hard. Really, really hard. Stainless steel frets are really, bloody hard.
While not exactly common, I’m seeing a bit of an increase in stainless frets and in requests for them. Because they’re so hard, they wear really well and last for ages. If you’re an aggressive player, who’s hard on frets, stainless steel frets might see you visiting me for a refret less often.
That said, stainless frets are incredibly difficult to work with. They’re tough to install well and are massively punishing on tools. A stainless refret will typically see me replacing tools that the wire has ruined. For these reasons, stainless refrets are quite a bit more expensive than a ‘standard’ refret.
Bling. Evo frets are gold. All the way through—it’s not just a plating. Evo wire, like the brass and nickel silver is a copper alloy. If you’ve got one of those periodic table shower curtains, you’ll easily parse its composition: CuSnFe1Ti. For those who failed to pay attention in science class, that’s copper, tin, iron and titanium.
On the hardness scale, Evo comes in slap-bang in the middle between nickel silver and stainless. It can be a good compromise as it’s a little easier to work with and therefore a little less expensive than a stainless refret. Its gold colour isn’t to everyone’s taste, however (although it can look great on the right guitar).
Fret Material Impact on Tone
Blah, blah, blah… Tone is subjective… Blah, blah.
Now, with that out of the way, here is the conventional wisdom:
Brass frets tend to have a solid, warmish tone while stainless steel frets can add a little brightness and, maybe, some slight sustain increase. Nickel silver, you’ll know and it tends to be the middle-of-the-road between the brass/stainless extremes. EVO fret wire sits somewhere between nickel silver and stainless in the tone spectrum.
My own opinion? I've come to believe that any alteration to your tone from different fret materials—if it exists at all—is massively subtly (a splendid oxymoron). I've swapped out a lot of frets and, personally, I don't think I could tell the difference in sound.
If you can, great but I have to emphasise subtle on this. Do not expect huge shifts in tone.
Bottom Line: Is it worth upgrading?
As I mention in the Fret Size article, if your frets are sufficiently worn to warrant a refret, you might want to have a think about materials.
Personally, I wouldn’t recommend a change in fret material purely to change your tone as the changes won’t be very marked. Realistically, an increase in hardness/lifespan is the main reason to consider a change.
And that said, in my opinion, stainless steel is overkill for most players (and the increase in installation cost must be considered). If you wear through frets really quickly, it can be justified but there’s a reason nickel silver is the default on pretty much every guitar made—for most people it’s perfectly fine.
Evo wire can provide a middle-ground that’s hard-wearing and not quite so expensive as stainless but some don’t like the colour (although that’s exactly the reason others choose Evo).
The bottom line on this one is: Unless you’ve got a particular reason to change materials, it’s just fine to stick with nickel silver.