High carbon or low carbon?

[ShannonH]

I'm buying some steel for both polepieces and blades, and am totally confused as to which to get high or low carbon steel. The preference for screws seems to be 1018 or 1021, but then I see some folks prefer 1008. What your take and why do you prefer?
Thanks

Shannon

[Joe Gwinn]

I'm buying some steel for both polepieces and blades, and am totally confused as to which to get high or low carbon steel. The preference for screws seems to be 1018 or 1021, but then I see some folks prefer 1008.

The higher the carbon the brighter the pickup. In cold-rolled steel alloy numbers, in "10xx" the xx is the amount of carbon expressed in hundredths of a percent, so 1018 has 0.18% carbon by weight.

[ShannonH]

perfect

The higher the carbon the brighter the pickup.

That's what I was looking for! Thanks Joe

[belwar]

There are some great sounding alloys out there too. Check out 12L14, it sounds great and machines easily because of the addition of a little lead. Great for slugs. 1018 for humbucker keepers is very good as well - As close to PAF accurate as you can get.

I've been thinking of messing around with a dual blade mini bucker. I was going to use 12L14 on the North side, and 1018 on the South side. Im not set on the 1018 yet, I may use a lower carbon steel then place it in a 1018 keeper.

Bel

[ShannonH]

12L14

TCheck out 12L14, it sounds great and machines easily because of the addition of a little lead. Great for slugs. 1018 for humbucker keepers is very good as well - As close to PAF accurate as you can get.

I've been thinking of messing around with a dual blade mini bucker. I was going to use 12L14 on the North side, and 1018 on the South side. Im not set on the 1018 yet, I may use a lower carbon steel then place it in a 1018 keeper.

Bel

They have 12L14 at McMaster in rod, but not in small enough sheet (1/4 in is the smallest) They do have 1008 in sheet, as well as 1018. I think I may try that combo. I'm fascinated at the difference the alloy can make. I have worked with high carbon and stainless for knifemaking, but this is all different. So many pickups, so little time!

[belwar]

I only make a few pickups for myself (models, not quantity), but I know in my limited design experience that it took changing the alloys to finalize my designs.

I found joes comment interesting, and i'd be interested to see if he had any science behind it. the last piece of my humbucker equation was the screws, and i had high hopes for the mojotone vintage pole piecs (advertised as 1010 but are actually 1022 verified with xray spectroscopy) but they were muddy and dark. I also tried low carbon screws and they were much better, and livelier. Though the screw i finally settled was mid carbon (somewhere around .20), it had a higher magnanese content - I think that was what did it for me.

The original PAF keepers had a high ammount of maganese which is not in steels of today. I *think* what I did was move the maganese to the screws instead of the keeper and I still maintained that trebly, but not brittle sound. The above is a total guess/theory, and i'll work on proving it at somepoint - However i'm very happy with my current outcome. :>

[FunkyKikuchiyo]

I'd like to know what some people are hearing between high/low carbon, because it isn't really what I hear. I've made some pickups with low carbon and some with high carbon, and I have heard the same muddiness in each. There was a certain shrill pick attack that was present in the high carbon, and it didn't seem to charge magnetically as well (the whole permeability thing) but just saying one is brighter and one is darker seems overly simplistic by what I've experienced. Maybe I just haven't made my experiments scientific enough...

Here's a wild guess - it might be one of those things like alnico alloys where the actual alloy number doesn't always tell you enough and that is isn't a one-dimensional scale. If belwar is right about the manganese then that would show it right there. One of these days I'll buy up a bunch of different alloys, but right now my experiments are burning a hole in my pocket, so I must pace myself.

[ShannonH]

another thought

Something I have considered is that the difference might be in the annealing. A hardened steel has a very specific crystalline structure. When softened (annealed) the carbon molecules separate slightly and the crystal matrix goes away in large part. This could allow the magnetic field to flow in a more "scattered" pattern, keeping the screech down. I have no empirical evidence, but I remember in "Guitar Electronics" that Bill Armstrong talked about an alloy he found for his blades that allowed for perfect magnetic flux. I assume he meant the magnetic field was largely un-interrupted by the steel. I am building an all slug pickup that I will try with annealed and hardened screws to see what the difference is.

[David Schwab]

I've made some pickups with low carbon and some with high carbon, and I have heard the same muddiness in each. There was a certain shrill pick attack that was present in the high carbon...

There you go. It's not going to magically make a dark pickup bright. Usually when you want to warm up a pickup you go for the low carbon steel.

I tried some magnetic stainless blades in some pickups I made, and didn't like the tone. The top end and upper mids were harsh. The exact same pickup with 1018 blades was perfect, and also allowed me to wind less turns on the pickup to open it up more. I had overwound it a bit to attempt to warm it up.

So muddiness has more to do with too much wire on the coil, and/or the magnets used.

[belwar]

Something I have considered is that the difference might be in the annealing. A hardened steel has a very specific crystalline structure. When softened (annealed) the carbon molecules separate slightly and the crystal matrix goes away in large part. This could allow the magnetic field to flow in a more "scattered" pattern, keeping the screech down. I have no empirical evidence, but I remember in "Guitar Electronics" that Bill Armstrong talked about an alloy he found for his blades that allowed for perfect magnetic flux. I assume he meant the magnetic field was largely un-interrupted by the steel. I am building an all slug pickup that I will try with annealed and hardened screws to see what the difference is.

Do you have a method of making sound clips? I would really like to hear your research should you want to share.

bel.

[David King]

I think a lot of what we hear is the frequency peak in the bright-sounding band of 3-5KHz. If you change something in the pickup that moves the peak a bit higher we actually hear less well in that upper area so the pickup actually sounds darker to us when in fact it's a brighter pickup on paper.

[Mike Sulzer]

I think a lot of what we hear is the frequency peak in the bright-sounding band of 3-5KHz. If you change something in the pickup that moves the peak a bit higher we actually hear less well in that upper area so the pickup actually sounds darker to us when in fact it's a brighter pickup on paper.

If you move the resonance above 5 KHz, it sounds less bright, mostly due to the limitations of the guitar speaker.

But if you damp the resonance more (higher conductivity steel) it also sounds less bright.

[jbforrer]

Greetings,

Interesting discussion. I'm no pickup expert, just a hobby, as someone once said "you're just an old eccentric musician working on his sound".

When a permanent magnet is used to induce magnetic field in steel, you are dealing with the B/H curve. That characterizes the resultant magnetic field strength eminating from the steel. It is not linear, and there is a saturation point, i.e., increasing the strength of the permanent magnet will not increase more magnetic field in the steel beyound a certain point. The B/H relationship is affected by carbon content. Lower carbon yields slightly stronger fields. You have the option; either you need a bigger field or a weaker one.

Google "Magnetic properties of low carbon steel" for interesting tidbits on this topic including the issue of Eddy current losses and the use of Silicon steel that may be useful when making blades for pickups.

Regards.

JBF.

[ShannonH]

Do you have a method of making sound clips? I would really like to hear your research should you want to share.

bel.

I do and I will. for this type of thing I plug my amp into an m-audio interface and record straight to garageband, no effect, no frills. I'm looking for tonal nuance. then it's to low compression mp3. In the next couple of weeks I'll do it.

[automan]

Low compression mp3 is still compressed. You should save your files in the flac format.