Saddle Sore

[fretlessman71]

I could swear I can hear the difference between chrome-plated brass saddles and pure brass saddles. The non-chromed brass saddles seem to have more of a tone focus (I can't find any other way to describe it). Does anyone else have this experience or am I just crazy (or both)?

 

[guts]

I don't think you're crazy, and I think that you are hearing a difference, but I think that the difference is coming from your mind.

The thickness of the chrome layer is something like 0.0001 of a millimeter. It's barely there.

 

[JRA]

I could swear I can hear the difference between chrome-plated brass saddles and pure brass saddles.

ok.

 

[Bruce Johnson]

You aren't crazy, at least about this! You can, in some cases, hear slight differences in the tone on the strings from saddles made of different metals. But it's not from the density of the metal, or resonance down through metal, or anything like that. It's from the hardness of the metal right at at the fulcrum edge where the string contacts.

A harder metal, if cut correctly, will make a sharper edge for the string to rest on. The hardest metals, like steel, will bring out a little bit of extra ring at the very high end. Softer metals, like brass or especially aluminum, will dull out that high end ring.

It's not a dramatic difference, just a subtle amount of tingle at the top. And you'll mostly hear it with bright roundwounds and bright clear pickups. On a naturally wooly bass, you won't notice the difference.

Chrome plating, with the nickel base under it, is a hard coating. If the brass saddle is cut correctly to a sharp edge, chrome plating it hardens the edge and keeps it sharp. You are hearing the difference between a hardened knife edge and a soft metal knife edge.

 

[guts]

Can you imagine a knife where the hardened part of the knife was 1/100th the thickness of a human hair? Do you think it would stay sharp?

It's like covering a piece of bread in aluminum foil. Aluminum is harder than bread, but bread covered in aluminum foil is still squishy.

 

[fretlessman71]

You aren't crazy, at least about this! You can, in some cases, hear slight differences in the tone on the strings from saddles made of different metals. But it's not from the density of the metal, or resonance down through metal, or anything like that. It's from the hardness of the metal right at at the fulcrum edge where the string contacts.

A harder metal, if cut correctly, will make a sharper edge for the string to rest on. The hardest metals, like steel, will bring out a little bit of extra ring at the very high end. Softer metals, like brass or especially aluminum, will dull out that high end ring.

It's not a dramatic difference, just a subtle amount of tingle at the top. And you'll mostly hear it with bright roundwounds and bright clear pickups. On a naturally wooly bass, you won't notice the difference.

Chrome plating, with the nickel base under it, is a hard coating. If the brass saddle is cut correctly to a sharp edge, chrome plating it hardens the edge and keeps it sharp. You are hearing the difference between a hardened knife edge and a soft metal knife edge.

Love this kind of education and discourse! Thanks Bruce.

So I believe Chrome is softer than Brass..... you're saying that the difference is enough that it would account for the difference in tone? (I've never heard of steel saddles... yikes...)

 

[fretlessman71]

Can you imagine a knife where the hardened part of the knife was 1/100th the thickness of a human hair? Do you think it would stay sharp?

It's like covering a piece of bread in aluminum foil. Aluminum is harder than bread, but bread covered in aluminum foil is still squishy.

Not sure of your point here, but curious - do you mind elaborating?

 

[guts]

The mechanical properties of the coating do not negate the mechanical properties of the substrate. Especially since a chrome coating is cosmetic and super thin.

 

[Bruce Johnson]

Can you imagine a knife where the hardened part of the knife was 1/100th the thickness of a human hair? Do you think it would stay sharp?

It's like covering a piece of bread in aluminum foil. Aluminum is harder than bread, but bread covered in aluminum foil is still squishy.

Can you imagine a steel knife edge that's been case hardened, to maybe a thousandth or two thick?

The brass saddle can easily support the vertical load of the string from squishing it. The chrome/nickel plating keeps the very edge from getting worn dull by the string moving over it.

 

[Bruce Johnson]

The mechanical properties of the coating do not negate the mechanical properties of the substrate. Especially since a chrome coating is cosmetic and super thin.

The chrome/nickel plating reduces the wear on the surface, when being rubbed by a steel/stainless string.

 

[guts]

You understand we're not talking about thousandths of an inch here. We're talking about 0.000004 of an inch. Millionths of an inch. Can you visualize you know how thin that is?

 

[Bruce Johnson]

So I believe Chrome is softer than Brass..

Chrome itself is much harder and more wear-resistant than brass. Now, Show Chrome plating, as used on instrument parts, only has a very thin layer of chrome, but it's over a thicker layer of nickel. Nickel is a very tough abrasion-resistant metal.

 

[Bruce Johnson]

You understand we're not talking about thousandths of an inch here. We're talking about 0.000004 of an inch. Millionths of an inch. Can you visualize you know how thin that is?

Guts, I'm a mechanical engineer and machinist, and I've been building metal things all my life. Show Chrome plating (which is chrome/nickel/copper) ranges in thickness from about 0.002" to 0.004".

 

[guts]

Do it yourself dude. It takes like ten seconds. You're on the internet.

 

[Bruce Johnson]

Do it yourself dude. It takes like ten seconds. You're on the internet.

Dude, I've been machining up bass bridges and saddles and parts for many years, and having them plated. I've been working with plating companies and personally measuring parts before and after plating. Show Chrome plating is usually between 0.002" and 0.004" thick, depending on the plating company and what you ask for. I do this for a living, and I know what I'm talking about.

Just to be clear for everyone, Show Chrome is the name of the overall plating process that you get when you have parts "chrome plated" for shiny looks. It's a multiple layer plating process: Usually a base layer of copper, followed by a thick layer of nickel, and then a thin flash layer of chromium on top. The nickel is the real strength, hardness, and wear resistance of the overall plating. The chromium is just there to brighten the color and keep the nickel from tarnishing. The thickness of the chromium itself varies from place to place, but is typically a half-thousandth (0.0005"). The nickel and copper make up the rest of the thickness.

So, when I talk about the thickness of Show Chrome plating being 0.002" to 0.004", I mean the thickness of the whole thing, all the layers, not just the chromium.

And when I talk about the hardness of the plating keeping the edge of the saddle sharp, I mean the whole thickness of the plating, including the nickel.

There's a different plating process called Hard Chrome, in which a very thin coating of chromium alone is put on steel or other metals. It's done to make the part more abrasion resistant, or to build up a worn part. Hard Chrome isn't shiny or mirror-looking, just kind of a dull silver. But that's not what we're doing here on instrument parts. The shiny, decorative chrome is the Show Chrome process.

 

[guts]

Oh I misread you, my bad. You were referring to the plating as "show chrome". Not asking me to show you.

The plating can be and usually is much thinner for other applications. It can be as little as a few atoms thin. I guess that's not the case here.

Although references are saying that decorative chrome is between 0.005 and 0.01 mils. Not thou. Are you sure you don't have the unit wrong? Do they really put that much more chrome on guitar parts than they do on motorcycles and cars?