<p>Stainless steel is not immune from corrosion (&quot;rusting&quot;), only has it a highest resistance. What you see is likely <a href="https://www.ddcoatings.co.uk/2276/what-is-pitting-corrosion" rel="nofollow noreferrer">pitting corrosion</a>, and it does occur especially in stainless steels. I can only guess what happened, but in my opinion some salts remained on the surface after water evaporated and that caused the corrosion.</p>

CC BY-SA 4.0
2023-12-20T16:09:31.560Z
2023-12-20T16:09:31.560Z
El_Muntagnin
<p>Stainless steel is &quot;stain <strong>less</strong>&quot; not &quot;stain <strong>free</strong>&quot;. There are many different grades of stainless steel with varying degrees of stain resistance.</p>
<p>Stainless steel is made from steel (iron) alloyed (mixed) with nickel, chromium and molybdenum. In general, more of the alloy metals mean more corrosion resistance and higher cost.</p>
<p>Stainless alloys which can be hardened for use as knives are magnetic and more susceptible to corrosion.</p>
<p>Stainless alloys which cannot be hardened are used for most kitchen applications. They are non-magnetic or only weakly magnetic. These alloys are more resistant to corrosion than the magnetic alloys used for knives.</p>
<p>If you want corrosion resistance, go for 316 alloy as opposed to the more common 304 alloy. Unfortunately, consumer goods are seldom labelled with the alloy number and there is no easy way (like magnetism) to distinguish them.</p>
<p>Don't put Stainless knives through the dishwasher. Hardened stainless has little resistance to chloride pitting</p>

CC BY-SA 4.0
2024-01-02T07:06:59.007Z
2024-01-02T07:06:59.007Z
Woody
<p>I've been using a stainless steel moka for the last couple months. A fee days ago some spots started to appear (I believe after putting it on the stove without water by mistake). Is the pot rusting? <a href="https://i.sstatic.net/zWCgC.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/zWCgC.jpg" alt="enter image description here" /></a></p>

CC BY-SA 4.0
2023-12-19T00:56:12.720Z
Do you know the manufacturer name or model of this moka pot?
R Mac
CC BY-SA 4.0
2023-12-20T11:35:01.860Z
Intenca from bon vivo
Brugarsa
CC BY-SA 4.0
2023-12-21T12:34:55.377Z
Thanks. Also does your home source water from a well or from a municipal water treatment facility?
R Mac
<moka>
Can a stainless steel moka rust?
Brugarsa
# Can a stainless steel moka rust?

(Asked by: username_0 on 2023-12-17)

I've been using a stainless steel moka for the last couple months. A fee days ago some spots started to appear (I believe after putting it on the stove without water by mistake). Is the pot rusting? [![enter image description here](https://i.sstatic.net/zWCgC.jpg)](https://i.sstatic.net/zWCgC.jpg)

**Tags:** moka

> **Comments:**
> **username_1**: Do you know the manufacturer name or model of this moka pot?  
> **username_0**: Intenca from bon vivo  
> **username_1**: Thanks. Also does your home source water from a well or from a municipal water treatment facility?  

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## 2 answers

### Answer by username_2 on 2023-12-20. Score: 1

Stainless steel is not immune from corrosion ("rusting"), only has it a highest resistance. What you see is likely [pitting corrosion](https://www.ddcoatings.co.uk/2276/what-is-pitting-corrosion), and it does occur especially in stainless steels. I can only guess what happened, but in my opinion some salts remained on the surface after water evaporated and that caused the corrosion.


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### Answer by username_3 on 2024-01-02. Score: 1

Stainless steel is "stain **less**" not "stain **free**". There are many different grades of stainless steel with varying degrees of stain resistance.

Stainless steel is made from steel (iron) alloyed (mixed) with nickel, chromium and molybdenum. In general, more of the alloy metals mean more corrosion resistance and higher cost.

Stainless alloys which can be hardened for use as knives are magnetic and more susceptible to corrosion.

Stainless alloys which cannot be hardened are used for most kitchen applications. They are non-magnetic or only weakly magnetic. These alloys are more resistant to corrosion than the magnetic alloys used for knives.

If you want corrosion resistance, go for 316 alloy as opposed to the more common 304 alloy. Unfortunately, consumer goods are seldom labelled with the alloy number and there is no easy way (like magnetism) to distinguish them.

Don't put Stainless knives through the dishwasher. Hardened stainless has little resistance to chloride pitting


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