High carbon or low carbon?

[Possum]

...

Yeah I have a whole binder of vintage steel microphotography, we did everything, all the tests. Microphotography, you have to polish a flat surface and use special acids, if I remember there are 3 different types of acids that will bring out the crystal structure so you can see it well. I aksed him if I could do this myself and it sounded too complex to mess with on a small scale for what I'm doing.

Hot roll and cold roll are two totally different things. Hot is in a soft form and cold roll is harder. Hot roll is a sloppy process with low tolerance for sizing. Grinding won't make hot sound cold :-) If you make alot of your own parts like I do, even in one batch of steel you find some that are easy to drill through and others of the same batch that are harder. Gibson's pickups changed in tone, in part because steel making got "better." So late TTops don't sound like the earliest ones. Earlier steel making was done in an open hearth Bessemer process, in 1968 the last one closed, Gibson's buckers changed about that time too, coincidence?

[RedHouse]

...Earlier steel making was done in an open hearth Bessemer process, in 1968 the last one closed, Gibson's buckers changed about that time too, coincidence?...

Well yeah, doesn't everyone know they came in and packed it all up and shipped it off to Area-51... that's where they keep all the nations stockpile of unobtainium.

[defaced]

Metallography is not fun, it is difficult to do well, it's expensive to setup, and I wouldn't wish it on anyone. I've had my fair share of polishing and etching samples.

Hot roll and cold roll are two totally different things. Hot is in a soft form and cold roll is harder. Hot roll is a sloppy process with low tolerance for sizing. Grinding won't make hot sound cold :-)

Right, I know they're different which is why I brought up hot rolled steel. If vintage steel was manufactured different, then looking to post processing operations like rolling could answer your question. If you have one hot rolled plate, one cold rolled plate that was say rolled to 2x what you actually wanted, and one cold rolled plate that was rolled to the thickness you wanted, the amount of cold working between he materials would be different, and as you've already said, sound different. Maybe vintage steel was rolled less than modern steel. Instead the steel was rolled less and machined to final shape because cold rolling tolerance weren't what they are now.

Now I don't have the slightest clue what vintage steel sounds like compared to modern cold rolled steel, but I've got a good grasp of how manufacturing processes affect material properties, so if the answer doesn't seem to be in composition, then I starting thinking about the 8 million other things that affect a material's properties, and go from there.

And to your steel making process point, steel is alot cleaner than it used to be with regard to P, S and O, but it's also got recycled metals in it which micro alloy and could play with things. If you're saying things changed right when the steel making process changed, maybe it's an impurity element concentration change?

Do you have that binder handy enough that you could post up what elements you tested for and testing method you used?

[Possum]

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Cold rolling processes vary and my metallurgist did talk about degrees of compression etc. but it doesn't really help to know that and unless you own an old time Bessemer open hearth steel mill you can't really do anything with the info anyway.

My binder of info is all private material, years worth of questions and answers, it all goes into my VL PAFs which even now are changing as I learn more stuff. Modern alloys are different enough than the old ones, keepers for instance were almost all higher carbon than what you get now. This changed as the times changed. the only thing you can do is buy material, if its sucks don't use it, if it sounds good use it.

[RedHouse]

Cold rolling processes vary and my metallurgist did talk about degrees of compression etc. but it doesn't really help to know that and unless you own an old time Bessemer open hearth steel mill you can't really do anything with the info anyway.

My binder of info is all private material, years worth of questions and answers, it all goes into my VL PAFs which even now are changing as I learn more stuff. Modern alloys are different enough than the old ones, keepers for instance were almost all higher carbon than what you get now. This changed as the times changed. the only thing you can do is buy material, if its sucks don't use it, if it sounds good use it.

Did I just read that right? you're saying you have a binder, with years of stuff, that all goes into your line of pickups, but it means nothing because everything has changed, and you just have to buy material and try it out like everybody else? it would logically follow that you must be going to give the "it's all in the metals" theory a rest then and make pickups with currently available materials?

I must have read this wrong, this doesn't sound like you Possum, you feeling ok today?

...somebody, check for pods...

[defaced]

Cold rolling processes vary and my metallurgist did talk about degrees of compression etc. but it doesn't really help to know that and unless you own an old time Bessemer open hearth steel mill you can't really do anything with the info anyway.

That's a shitty, but very true fact. You get what the steel mill makes. It's very difficult to get what you want anymore from materials manufacturers. I'm interested in the discussion from an academic point of view.

[JGundry]

There is a practical reason for using lower carbon steel for screws. A lower carbon steel like 1008 will give a nicer finished part than 1022 if they are made with a cold header.

[Possum]

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No, the metal is still extremely important and copying specs of those parts is important. But yeah, you have to get everything right, not just the steel. Without the right 3 alloys you're making something else, IMHO.

Here's what a microphoto looks like, this is the "bad" stuff I mentioned earlier, probably Chinese made, sounded really bright:

[David King]

Looks like a bad case of malaria to me..

[EtLa]

I think it was two years ago, anyway I did some anealing (magnetic permeabilty) test with 1018 studs that I cut myself.

Anealed > cut > re-anealed (because of a possum observation ) and like it was supposed to, standard 5000 turns coil show a higher inductance than the non annealed 1018.

I still have the picture of the studs and It was a pain in the *** to make.

[RedHouse]

Red House, no not backing off the importance of the metals. I do have a slight edge in that I can get microphotography done of anything I want to buy and I know what to look for. But I still have to listen to test pieces. The metals are important because there are basically 3 completely different alloys in PAFs in the magnetic circuit and its important to use those 3. Of course the 4th alloy is the magnet itself, and you know how much those can vary, though they are probably more consistent than steel batches. Another good reason to make your own stuff is that commercial parts like, say a big batch of slugs, you may be getting mixed batches of steel so some could be real dark and some real bright and you're at the mercy of where those slugs happen to randomly fall in your pickup. But yeah if you just get the metals right you're not suddenly going to get PAF tone, all the sizes have to be dead on and the coils have to be done right too.

Here is a typical microphoto of one alloy, not saying which, and this happens to be the bad stuff that was crap in pickups, looks like a bad pizza :

Oh ok, phew! ... I thought the universe was going out of kilter for a second there!

[defaced]

EtLa's comment, in addition to Possom's micro link up to something interesting. Possom's micro is of a highly cold worked steel with relatively small grains. EtLa's observation about inductance after annealing suggests to me that grain size is a possible factor. Grain size will change based on a time at temperature reaction, and if you furnace anneal a piece, it will have very large grains. I don't have a real metallurgy book on me at the moment, I might be able to dig up a graph of this if anyone's interested.

[Sheldon Dingwall]

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.

Would that be laminated silicon steel?

[Sheldon Dingwall]

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

How does the lead content affect RoHS compliancy?

[ShannonH]

i don't think so

Would that be laminated silicon steel?

My knife making texts indicate this is the case with any steel, but more so with higher carbon content.