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Discussion Starter · #1 ·
Why isn't there any Stainless Steel rotors.
To make Stainles Steel only takes about 5% nickle added.

I'm tired of that rusted look of my rotors.

I had the hubs of my rotors powder coated in high temp header paint a few months ago, and now that winter is gone, I notice that they've rusted over.

What is it about Stainless that they can't or won't make rotors out if it?
 

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Why isn't there any Stainless Steel rotors.
To make Stainles Steel only takes about 5% nickle added.

I'm tired of that rusted look of my rotors.

I had the hubs of my rotors powder coated in high temp header paint a few months ago, and now that winter is gone, I notice that they've rusted over.

What is it about Stainless that they can't or won't make rotors out if it?
Stainless steel also lacks iron, which is the reason it doesn't rust. Rust is iron oxide.

One reason I can think of is they would be insanely expensive.
 

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Stainless steel also lacks iron, which is the reason it doesn't rust. Rust is iron oxide.

One reason I can think of is they would be insanely expensive.
Stainless steel doesn't lack iron, it is actually predomainantly made up of Iron.

Depending on the grade of stainless steel it typically contains a minimum of 0.8% Cr (Chromium)

Cr is the main element added which enhances corrosion protection.

Im no expert but I dare say its due to the fact that cast iron has better thermal expansion properties then stainless steel, plus cast iron is a lot cheaper. Most after market BBK discs are just zinc coated.
 
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Stainless steel doesn't lack iron, it is actually predomainantly made up of Iron.

Depending on the grade of stainless steel it typically contains a minimum of 0.8% Cr (Chromium)

Cr is the main element added which enhances corrosion protection.

Im no expert but I dare say its due to the fact that cast iron has better thermal expansion properties then stainless steel, plus cast iron is a lot cheaper. Most after market BBK discs are just zinc coated.
Interesting. I learned something new today. +rep!

Why don't magnets stick to some stainless steel?

I shouldn't have said lacked, as in completely. But I thought it contained only a very, very small amount of iron depending on the grade. Possibly why my knives can stick to a magnetic strip but no magnets will stick to my refrigerator and I can't pick up stainless bolts/screws with my magnetic pick up tool.

/threadjack
 

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Discussion Starter · #6 ·
Steel come is various compositions or alloys. Iron is just one form or element of it. Stainless is another and contains 5% nickel. Nickel is not magnetic and somehow completely defeats the other magnetic properties of the steel, but somehow stabilizes it so that that it is not suseptible to oxidation.
 

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Interesting. I learned something new today. +rep!

Why don't magnets stick to some stainless steel?

I shouldn't have said lacked, as in completely. But I thought it contained only a very, very small amount of iron depending on the grade. Possibly why my knives can stick to a magnetic strip but no magnets will stick to my refrigerator and I can't pick up stainless bolts/screws with my magnetic pick up tool.

/threadjack
I don’t wish to get all too technical but Nickel isn’t what causes stainless steel to lose it’s magnetic abilities nor is it added to enhance corrosions resistance as I stated previously Chromium is what makes stainless steel stainless/corrosion resistant.

Nickel is added primarily to expand the austenite or gamma phase field when alloyed with iron.

The reason for stainless steel being parramagnetic (non magnetic) is not because it lacks iron, its due to the fact that it is trapped in a different phase (austentic phase) which is essentially due to the chemistry makeup required for s/s.

Mild steel/cast iron doesn’t reach this phase (austenitic) until it reaches the curie temperature which is above 769° C (mild steel loses its magnetic ability once it is heated to above 769° C) whereas stainless steel is trapped into this phase at room temperature. Therefore stainless steel at room temperature (or any temperature for that matter) is paramagnetic because of the phase it is trapped in.

Hope that makes some sense?!
 

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Only austenitic stainless steels are the non magnetic I think, there is also ferritic (semi magnetic)and martensitic (which is magnetic).
Also some stainless alloys still rust, they are just more resistant than plain carbon steels.

From what I have heard from motorcycle racing, stainless has a horrible coefficient of friction band because they are so hard and more fade as they get hot. When the brakes on a bike go...they are gone. Also as the material cools, you get more stress built up..warping. You can tolerate this on a motorcycle since the rotor is out in the open...and its just a floating ring. Expense of raw materials, poor performance, complexity of manufacture... I cannot think of a reason to go stainless after looking into it unless new technology is applied to the process.
 
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