Newbie question on steel (a bit long post)

[orangedrop]

Hi Guys, I’m a newbie here - I’ve been reading posts from most of the pages (48 all in all).
A short presentation of me would be that I’m 54 years old; I’ve been playing since I was eleven. For a while there I thought I would be the new EC - which didn’t happen and I’m glad I did not try harder (but it did affect my grades in school a lot). I’m still playing in a band and love every minute of it.
I’ve played many of the “originals” and have friends that own guitars from the late 50: ies. I would say I know good tone.
I’m playing Gibson’s mostly and currently play a beautiful LP ’58 RI through a BF Deluxe Reverb or a Tweed Deluxe.
I’ve owned and played many designers PU:s (Lollar, Wolfe, Lundgren (a Swede), SD, DMZio, Gibsons, Tim White) but never really reached the same level of tonal satisfaction as I did with a pair of early T-tops that I sold many years ago #( (or maybe it's just age :)

I’ve read and learned a lot here. I liked Dave’s tone on Youtube a lot. So, I ordered a pair from him (haven’t got them yet though ;).

Many posts here concerns the magnet wire but Dave talks a lot about, and always returns to, the steel/iron content in the PU - and this is my question. I do not expect you guys to give away trade secrets but a short introduction to the subject would be nice.
What is soft steel? I believe that is the term Seth Lover used. What is the difference between iron and steel? Who uses 1022 steel and who uses 1018? What’s the tonal difference between those two? Is there any other kind of steel that has favourable tonal properties?
If I take the iron nails that I saved from my old house (built 1905) and put them in a PAF replica – would they sound good? :rolleyes:

(One of the best post on this subject was http://music-electronics-forum.com/showthread.php?t=1684&highlight=1022 But I’m still not much wiser after reading that).

Bjorn Larsson
Sweden

[belwar]

Most of the time people talk about "soft iron" which is (I believe) a term from the 1930's to 1960's. I dont believe that is even a set definition of that term. Generally it refers to a low carbon steel of the cold rolled variety. There are really only a few options in the bracket today.. 1018 and 1022 are readily available in bar stock. It is possible to get other alloys, but not in a form that is usable to a pickup maker.

My current theory is that during WWII there were many different options for steel available, and now it is just not nessesary as 1018 and 1022 function for most everything.

The reason the variety of steel is important is that every part of conductive metal in the pickup changes the load on the magnet, which alters the tone. The more conductive metal, the more load on the magnet. I don't have a lot of experience in pickup winding, but from what I have read the differences between 1018 and 1022 are noticable, but not major. I personally would think that the size/shape of the parts would make more of a difference... In theory.

b.

[Possum]

Hang in there Bjorn, they're coming eventually :-) Making progress.....

From what I found, steel before 1968 was made in open hearth furnaces and had a peculiar chemcial content because of that. That kind of steel is no longer made. Thats all I'll say about that. Steels are like magnets, they will sound different depending on where and who made them. 1018 is the most common alloy these days, 1022 is real hard to find anywhere unless you have a good mill connection and you have to buy alot to get it. "Soft iron" was just a loose term back then meaning exactly that. PAF period soft iron has no direct replacement in modern times.

With different steels you just have to try them out and see how they sound in a pickup. I thought you could use an lCR meter to get a handle on that but alot of what happens is in the upper frequencies where the meter can't see. Steel is a huge subject, I've spent hours online googling and reading as much as I could understand; there are scores of kinds of steel you can try, it gets real confusing because there are about four different naming systems as to whats in the alloy. Its really been helpful to me to buy a small lathe and mill to make the parts myself, a good skill to have.

[David Schwab]

Hey Dave, do you have any experience with "oil-hardening" O1 tool steel?

(0.90% carbon, 1.0%-1.4% manganese, 0.50% chrome, 0.50% nickel, and 0.50% tungsten.)

I picked up some because there was a 3 week wait on 1018.

[orangedrop]

Thank you for replying.
So - I guess my “soft” iron nails from 1905 could be a good substrate to make PU parts from 

Are most PU:s coming from bigger manufacturers (read SD, DMZio) made of 1018 steel, (because that’s the steel that’s available)?

What are the tonal differences between 1018 steel and 1022? I know I read it somewhere but I can’t seem to find where.

[Possum]

Yeah iron nails from then would be great. I don't know what DM or Duncan use and they won't tell you for sure. 1018 is generally a bit darker and looser feel than 1022. 1022 can be real hard edged sometimes. But it all depends on what the other parts are made of as well, its a big jig saw puzzle....

[EFK]

Those iron nails, whether cut nails (90% post-1840/50) or actual forged (that would be pretty rare for 1905, at least here in US), are relatively low-quality iron which means they will have a high proportion of silicate/slag inclusions. Also, rust/corrosion has a way of working itself into these inclusions (think of them as veins or fibers in the metal) so that while you may cut and/or machine a piece down which looks clean, it may possess rust pockets or rusty 'threads' inside. I have no idea how this would effect the transference of magnetism from the magnet. Certainly worth a try but anything made from them will be a far cry from either electrical grade iron (which is beautiful but costs a fortune) or relatively 'clean' plain low carbon steel in the 1002-1010 range which you'll have to machine yourself.

[SK66]

Hey Dave, do you have any experience with "oil-hardening" O1 tool steel?

(0.90% carbon, 1.0%-1.4% manganese, 0.50% chrome, 0.50% nickel, and 0.50% tungsten.)

I picked up some because there was a 3 week wait on 1018.

To harden steel heat it until it is orange and no longer magnetic. Then plunge it into whatever cooling method is best for that steel (oil, water, room tremperature air). This will convert the austenitic steel to a full martensitic state. You don't want that...it's too brittle. You'll want to temper it back in an over at 350-425*f for aprox 30 minutes. The best way to determine when it is at the right temp is to clean up the metal before tempering and look for it to change to a straw brown color...(figuring fairly well tempered...light straw color for something like a knife). Ideally, placing the parts in hot ashes (aprox same temp as part) and allowing to cool from there very slowly...for what you are doing just leaving them in the oven and allowing it to cool slowly should do.

[David Schwab]

I don't want to actually harden it... I'm using it for pickup blades. I wanted to go with a lower carbon steel, but there was a long wait from McMaster-Carr, and I wanted to have something to work with, so I ordered a meter of the stuff.

I just haven't made it into a pickup yet.

[Possum]

David, I got some to try for a hoot. Probably won't be very good, I think its about 100 parts carbon, five times higher than 1022. But I'll try anything once....

[David Schwab]

It's 0.90% carbon. 1022 is Carbon 0.18 - 0.23%.

What do you hear in the higher carbon steels that you don't like? Is it harsher?

Of course this is for a bass pickup, and with neo magnets...

I'll be trying it out soon. I don't even know what I've been using with the latest pickup parts.

[Possum]

Judging by the 1022 screws I had made (not an acid test admittedly) and some 1022 slugs I've tried they are just to hard sounding, no sag, kinda flat harsh if that makes any sense. But I guess it depends on what and how you're using it. 90pts carbon is awful high...

[David Schwab]

Well I'll find out soon enough. Ironically I could have waited for the cold rolled steel bar.

I figured that the allen screws used in a lot of pickups are alloy steel which is harder than the low carbon stuff.

[Possum]

the stuff I got is W-1, its a bit higher carbon....

[Joe Gwinn]

I figured that the allen screws used in a lot of pickups are alloy steel which is harder than the low carbon stuff.Typically, the screw material will be something like 1045 "medium" steel, being 0.45% carbon.

Allen wrenches are made of steels such as 8650 chrome nickel alloy, at least the good ones are.

[David Schwab]

I have a box of black finish 10-24 allen set screws I got from McMaster-Carr, which look exactly like what you'd see in a DiMarzio pickup.

The box lists them only as "alloy socket screws, cup pt" so 1045 makes sense.

The O1 bar I have certainly seems as magnetic as the rest of the blades I've been using. I have no idea what they are, and they are also plated with something shiny.

I'll be working on the pickup in the next few days, so I'm curious to see how the new steel sounds.

[kevinT]

Both 1018 and 1022 steel is readily available to fastener manufacturers if you're having some fillisters made.

[David Schwab]

Still the big question is what does carbon content do to the tone, and why?

[Possum]

Carbon affects permeability right? If you have iron with alot of carbon in it, it can be magnetized and will stay that way and will resist being demagnetized by an opposing force. Pure iron on the other hand is really permeable and won't hold a magnetic charge and changes polarity really easily. How this affects tone I can't quite get a grasp on, maybe Joe can explain it.

[salvarsan]

Carbon affects permeability right? If you have iron with alot of carbon in it, it can be magnetized and will stay that way and will resist being demagnetized by an opposing force. Pure iron on the other hand is really permeable and won't hold a magnetic charge and changes polarity really easily. How this affects tone I can't quite get a grasp on, maybe Joe can explain it. Permeability is how well something conducts magnetism.
Higher permeability in a coil core means more inductance in the coil.

Coercivity is how well something resists demagnetization.
If something can hold a magnetic charge, it has enough coercivity to be useful.
Permanent magnets have high coercivity and 'soft' steels don't.

-drh

[Joe Gwinn]

Carbon affects permeability right? If you have iron with a lot of carbon in it, it can be magnetized and will stay that way and will resist being demagnetized by an opposing force. Pure iron on the other hand is really permeable and won't hold a magnetic charge and changes polarity really easily. How this affects tone I can't quite get a grasp on, maybe Joe can explain it.Qualitatively, anyway. The harder (physically) the steel, the lower the incremental permeability and the higher the bulk resistivity, both tendencies causing eddy currents to be reduced. So I would expect the harder steel to make brighter pickups, because the eddy current loading is reduced.

The more carbon in the steel, the harder it can be made.

I don't know how much of the effect on sound is due to the carbon percentage alone (regardless of physical hardness achieved) and how much is due the the degree of physical hardness achieved (regardless of how achieved, the extremes being medium carbon, severe quench, and no tempering versus high carbon, ordinary quench, and medium tempering).

[David Schwab]

Qualitatively, anyway. The harder (physically) the steel, the lower the incremental permeability and the higher the bulk resistivity, both tendencies causing eddy currents to be reduced. So I would expect the harder steel to make brighter pickups, because the eddy current loading is reduced.

Very interesting!

Bill Lawrence is always saying his blades are stainless steel, and his pickups are very bright. I don't know what kind of stainless he's using, but he must have picked it for a reason.

[Joe Gwinn]

Bill Lawrence is always saying his blades are stainless steel, and his pickups are very bright. I don't know what kind of stainless he's using, but he must have picked it for a reason.Most kinds of stainless steel are non-magnetic, but a few are magnetic. We ought to be able to figure out which one he uses. One common magnetic stainless steel alloy (widely used in knives) is 440C. Small quantities may be bought from sellers of knifemaking supplies.

Stainless steels as a class have relatively high bulk resistivities, which greatly reduce eddy currents.

Use of stainless steel would eliminate the need to plate or otherwise finish the blades to prevent rusting.

[David Schwab]

Stich always talkes about eddy currents, so I'd bet that's the reason he uses that type of steel.

I have a few of his pickups with the blades, and they don't appear to be plated. They look like stainless steel.

One pickup is non working, so I could take it apart to access the blade.

[dpm]

there's some good info on ferritic stainless alloys here - http://www.cartech.com/ssalloys.aspx


Seems 430F and 430FR could be interesting to experiment with

[Joe Gwinn]

Stich always talkes about eddy currents, so I'd bet that's the reason he uses that type of steel.

I have a few of his pickups with the blades, and they don't appear to be plated. They look like stainless steel.

One pickup is non working, so I could take it apart to access the blade.If you do, consider having the blade composition analyzed by a steel supplier.

[defaced]

An independent lab should be able to do chem analysis if they do metallurgy work. OES (optical emission spectroscopy) is a good technique to get chem results for most steels. This technique will not pick up trace elements but it will get all of the big players. Where I get my stuff done for work, a full workup costs ~100 bucks for steel.

Use of stainless steel would eliminate the need to plate or otherwise finish the blades to prevent rusting. Some martensitic and ferritic stainlesses will rust on the surface if the Cr content is low enough (~12-14 wt%). If you want a ferritic stainless that will not rust, look for one with a Cr content above 16-18 wt%.

[Possum]

Did anyone try the stainless steel slugs SK sells?

[salvarsan]

Some martensitic and ferritic stainlesses will rust on the surface if the Cr content is low enough (~12-14 wt%). If you want a ferritic stainless that will not rust, look for one with a Cr content above 16-18 wt%.At the low magnetic field strengths in pickups, magnetic permeabilities
of soft steels and type 400 stainless are in the same ball park.

The means that type 400 slugs and blades will work okay in a pickup
and that they will sound different enough from type 1000 steels to be
worth exploring.

Type 413 and 416 are commonly available and take a very high polish -- nickel plating is unnecessary.

Many machinists provide type 413 parts at reasonable cost.

-drh