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Alumite process? Anyone heard of it?


Q. Hi everyone,

I've been jumping all over the Internet looking for this answer and I cannot find a truly reasonable answer for this.

What is Alumite? Is it an anodic process like I've seen stated some places? I have a gentleman that asked me about this process and I cannot give him the total answer because no matter how hard I look I cannot find the true source of this.

So far I've figured that its originated from an Asian country, I do believe Japan. I've seen it advertised on certain products for various things. I've seen mention of it being a Al2O3 base product. Which means of course aluminum oxide, but is it an anodizing process? Or is it a mechanical process that uses aluminum oxide based media to produce a desired finish?

I'm really confused on this one. I've seen it mentioned as being available already "fused chemically" to aluminum alloy sheets. Which indicates to me its an anodizing process of 20-30 micron (again its about .001 thk in that regard, so it tends to make me think anodic process again).

Anyone know the originator of this process if it is an anodizing process? Somewhere I can find out if there are patents on the process and if so who I can contact about licensing the rights to the process.

I'm truly lost on this one, somebody out there has to know. You guys are too smart to let this one pass you up. Help me please.

As always thanks in advance for your help and I appreciate as fast and accurate response as you can provide.

Matthew Stiltner
- Toledo, Ohio

A. Good afternoon,

I have used the process to coat mild steel furnace retorts to make them resist ammonia [on eBay or Amazon] attack in the Nitriding process, it looked very mush like a physical deposition rather than chemical (electrolytic). I will try to find the company who carried out the process - this was 10 years ago. In any case I will make some enquiries.

Best Regards

richard buster
Richard Buster - Wolverhampton, United Kingdom


A. Viz my previous comments, I have contacted the company which carried out the process for me and they metal sprayed Aluminium onto the mild steel products and call it Aluminizing - which you are probably already familiar with. However, they believe that it is basically the same process. Sorry I could not be more help.


richard buster
Richard Buster - Wolverhampton, United Kingdom

A. Do you mean Alumilite ?, if so these are anodising processes as developed by Alcoa, there area range of processes under this name, Alumilite 225, 226 for wrought alloys and Alumilite 725, 726 for cast alloys you should be able to get more info from Alcoa of from where I got my info from, The Surface Treatment and Finishing of Aluminum and Its Alloys by S. Wernick, R. Pinner, P.G. Sheasby


Richard Guise
- Lowestoft, U.K.


Q. "Do you mean Alumilite?"

Richard(s) :-)

No it's not an Alumilite process. I asked myself, and he spelled it out for me. Its Alumite. Like I said before I've seen this as being a feature on car grills for aftermarket automotive things.

I also don't think its aluminizing. I know what that is, and its common on stainless steel, they use it on headers and exhaust systems on high performance vehicles and on aftermarket there also.

I'm really puzzled now. I got my hands on a few of these and checked it over visually. It looks like a duck, and quacks like a duck (anodize being that duck, a clear anodize as a matter of fact) but I still can't tell if its a duck.

I'm gonna see if I can't get this thing cut up and checked out for me. By looking at it and examining the texture the finish looks to be a clear anodize with a lightly etched matted finish. But then again I'm not sure what this Alumite stuff is. You can see where I found the little information I had available by checking Yahoo and searching for Alumite. That'll give you a listing of some of the stuff I saw about this process.

If it was an Alumilite process I already use that as a basis for my anodizing processes, so that wouldn't be a problem to work with. But I'm still real puzzled.

I appreciate the help guys, I'm still lost on this one though. I'm gonna keep nosin' around and if I find anything I'll let everyone know for your own reference. Might come in handy one of these days, ya never know.

Matthew Stiltner
- Toledo, Ohio

A. On my search engine by MSN, I see a Japanese company listed who makes Alumite treated aluminum name plates. They appear to be a conventional anodize with organic dye sealers. Does not appear to be a company offering to process other's materials, nor doing process licensing, however.

W. Carl Erickson
- Rome, New York


A. You can visit the following URLs to see different meanings for Alumite!... There is a solder called Alumite, there is a surface finish also called Alumite...

Unfortunately, the ones for surface finishing is in Japanese language and I could see no English link.

Timur Ulucak
aluminum extrusions & finishing - Istanbul, Turkey

thumbs up signSome trademark attorney somewhere may be howling in frustration that none of the industry experts visiting this popular finishing site knows what an 'Alumite' finish is supposed to be, or can find a conclusive reference to it among the world's billion and a half web pages!

The page referenced above says:
On the surface of aluminum and or aluminum alloy, porous layer is created by anodizing treatment, and then chemically stable surface layer is obtained by plugging or sealing that porous layer. This metallic surface treatment process and or the product produced by this process is called Alumite. This sealing treatment is done by high pressure steam and or by boiling water added with small special chemicals in order to seal and or plug the porous surface to improve corrosion resistance."

Numerous other pages from Japan refer to Alumite as a sealed anodized aluminum finish. Some say it's 'pearl white', others say it's the 'familiar light golden yellow' that has been known since 'the beginning of the post-war period'.

At this point my suspicion has to be that 'Alumite' is a colloquial term long used in Japan, simply meaning 'anodized aluminum'. But if someone owns the trade name "Alumite", referring to a non-generic anodized aluminum finish, we're waiting to credit it.

Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

A. Coming back to this one after reading letter 7201, I did find in a trade directory the following info,

Alumitec - Organic Seals for anodised aluminium from a company called Alumitec products Corp based in Torrance California.


Richard Guise
- UK

A. I did a quick check of US patents for "Alumite". The first hit that I checked, US3634208:COLORING METHOD OF ALUMINUM ANODIC OXIDE COATING FILM, Jan. 1972, states in the first sentence of the background: This invention relates to a method for coloring an aluminum anodic coating film which is hereinafter called "Alumite." The examples use various electrolytes (e.g. oxalic acid, sulfuric acid) to form the Alumite layer. This and other patents reveal that anodically formed aluminum oxide (Alumite) is porous. So, there really is quite a lot of information about "Alumite" on the Web and in the patent literature.

David Strawser
- Ramat Gan, Israel

Q. Hi,

I was reading your information and wondered if Alumite is the same as Alunite. A mountain stands over the town I live in and the name of it? ALUM Mountain. ALUNITE was mined here from 1878 - 1927. For more information about Alum Mountain, Bulahdelah go to although this may confuse the issue for you even more...

M. Burrows
- Bulahdelah, NSW Australia

A. Alumite is a product that can be attached to metals, the Adhesion technique is the interesting part however. It attaches to metal not by a chemical bond but an actual metal bond, the strength of the metal being attached to. Think of it as micro webs weaving through any open spots available between the flakes of Alumite. If metal is covered by Alumite and current is passed through the Alumite micro thunderstorms occur between the metal surface (to be coated) and the layer of Alumite, this is due impart to the nonhomogeneous molecular make up of the metal. Thus making metal webs between the flakes of Alumite and the metal.

Curtis Young
- Torrance, California, USA

I appreciate your response, Mr. Young, perhaps you are claiming it is microarc oxidation. But at this point, unless someone can point to a trademark, none of us are either right or wrong about what "alumite" means because the word is being so widely used interchangeably with 'anodizing' that no one except a trademark holder can argue that it is different :-)

Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

A. Alumite is a generic name given to aluminium oxide films produced by anodising. It is a colloquial term used to describe anodic films in some countries.

Phil Wade
High Emissivity Alloys - Westbury, Wiltshire, UK

A. Some types of Alumite have a very low thermal impedance v/s infrared radiation, specially at low-frequencies called "far infrared". It is demonstrated that using certain types of Alumite on heating applications, an interesting energy saving is obtained.

mario maggi
Mario Maggi
High-emissivity Alumite - Milan, Italy

Q. I am a Metallurgical Eng. suggesting various coatings to be applied to Automotive steering and suspension systems. We have an application for an anodizing process to prevent wear and galling. My question: is Almite and Alumilite coatings (anodizing) the same coating / process? Both coatings (as I understand it) are used for corrosion and wear resistance. Is there a source in the USA for the ALMITE process?

Gil Chrostowski
Automotive Steering -Suspension - Sterling Heights , Michigan, USA

thumbs up signAs an aside, and by way of introduction, we have dozens of requests at for info about "muric acid" and "muratic acid" (muriatic acid) and "de-cro'-tif chrome" (decorative chrome) --bastardizations that gradually grew far enough away from the original as to take on a life of their own.

My own belief is that Alumilite is an Alcoa trademark covering some specific anodizing parameters; that alumite is a generic term long used as a synonym for anodizing, and possibly a bastardization of Alumilite; and that almite is just a further bastardization of alumite :-)

If a trademark holder disagrees, we'll be happy to acknowledge their ownership of the terms they claim.

But what happens in cases like this is that people google the term and then they write us and demand that we all acknowledge their findings, and that we restrict our usage of the terms to match their understanding :-)   It's increasingly obvious that the terms are often used with multiple meanings and broader meanings than individual readers would like.

 Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

A. Hi,

The following is the Japanese Translation on an article on ALumite.

" A Method of anodizing aluminum or an alloy thereof in an aqueous solution of nitric acid, sulfuric acid or chromic acid thereby forming a corrosion resistant oxide coating film mainly with an aim of improving the corrosion resistance thereof has been known as an alumite treatment".

Hopes this help.

KK Tan
- Malaysia

A. Hi

this might help

Keshava Prasad M
- Chennai, India


thumbs up signThanks, Keshava, but it didn't help me, I don't think. It seems they call anodized aluminum 'alumite' in Japan, and by using that word, which other countries don't use, they can claim that Japan invented the product without actually distinguishing it from anodized aluminum :-)

But actually, I can't find a good claim to the invention and early history of anodized aluminum. If anyone has history, please point me to it.

Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

A. I don't know if anyone's still interested or if this helps at all, but I'm a Japanese Patent translator and I came across this thread by googling the word "alumite" because I wanted to find out more about it after seeing it in a patent I'm translating. The Japanese kanjis that correspond to "alumite" in the dictionary literally mean "anodized film" or "anodized membrane." Then there's a short definition in the dictionary that says an alumite is "an oxide coating created electrochemically on the surface of aluminum." It also has "alumite treatment" as the practice of "forming a corrosion-resistant oxide coating on the surface of aluminum."

In the patent I'm dealing with, the alumite is used on a bicycle sprocket, and the big ring-shaped part constituting the main bulk of the sprocket is made out of an aluminum alloy and has an alumite formed on the surface.

My two cents, for what it's worth.

Ben Norman
- Salt Lake City, Utah


A. Hi

Recently I had an opportunity to work for a Technology Transfer project, the technology that transferred from an automotive parts manufacturing company, Japan to a company in India. One of the components to be "Hard Alumite" treated as per the drawing.

The so defined process actually carried out using about 300 g/L Sulfuric Acid electrolyte with temp ranges from 13 - 17 °C.
The microhardness achieved was about 250 - 300 VHN.

Japanese pronounce it as "Hard Arumitu".

Normally hard anodizing is carried out at almost freezing point, hardness should be much more higher than 300 VHN.
So, I feel they follow their own methodology to define a process,rather following the international standards.

Keshava Prasad M
- Chennai, India

A. "Alumite treatment" is the practice of "forming a corrosion-resistant oxide coating on the surface of aluminum" in Japan as indicated by Norman from Utah. I am a translator and video producer for Nippon Light Metal company in Japan and have often come across the term describing the process in my Japanese video scripts. Hope this helps.

Mal Adams
- Kakegawa, Shizuoka, Japan
July 21, 2011

A. Shimano has the following this on some models:

The fishing reel comes with 2 spools, both of which are constructed from aluminium, which goes through an ALUMITE process to improve corrosion resistance even further.

But as I read earlier, Japan uses the word "alumite" to describe anodizing. Confusing to say the least.

- Quebec, Canada
August 27, 2011

A. Alumite is a type of Solder used to bond aluminum I believe. I found this company online that has the trademark on the name so I'm guessing that they might have a good idea on what you're looking for.

Hope it helps!

Bill Thom
- Emlenton, Pennsylvania
January 25, 2012

Hi, Bill. The use of the word "alumite" in that field seems to have no effect on the word "alumite" in the field of discussion (anodizing of aluminum); but when you say "has the trademark on the name", you raise yet another interesting topic: the difference between ® and ™.

Per, "If you claim rights to use a mark, you may use the "™" (trademark) or "SM" (service mark) designation to alert the public to your claim of ownership of the mark, regardless of whether you have filed an application with the United States Patent and Trademark Office (USPTO). However, you may only use the federal registration symbol "®" after the USPTO actually registers a mark, and not while an application is pending."

So kappalloy "claims" the trademark; but they don't "have" it. So says - "The Home Page of the Finishing Industry®"  :-)


Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey
January 26, 2012

Q. I recently received an RFQ from a customer requesting this ALUMITE finish then clear coat on an Aluminum Roof Rail for an OEM. Attached to the RFQ was a Spec TS430-02-002 issued 8/28/2011. It appears from this spec that Alumite is a Paint Film that either has a clearcoat applied over it or can be sealed much like standard anodizing. Has anyone heard of this? I am trying to get information on this process, however, the more I read the more confused I am getting. - Thanks

Mike Bucklin
Metal Finishing - Huntsville, Alabama, USA
August 13, 2014

August 2014

thumbs up signHi Mike. I think the best approach is to agree to finish it per TS430-02-002 or whatever spec they wish, but not to commit to determining, arbitrating or agreeing to what "Alumite" means :-)


Ted Mooney,
Ted Mooney, P.E.
Striving to live Aloha - Pine Beach, New Jersey

A. It may be something simple as a typo. Alcoa calls their anodizing processes Alumilite.

Marc Green
Marc Green
anodizer - Boise, Idaho
August 28, 2014

A. A company in Japan (UACJ.Co.JP) implies Alumite coating can improve both wear, corrosion resistance and has a "Lubrication Property"

Robert Bingham
- Green Valley, California USA
January 2, 2017

January 2017

thumbs up signThanks Robert. And the Chinese Whispers continues.


pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha - Pine Beach, New Jersey

"The Surface
Treatment &
Finishing of
Aluminium and
Its Alloys"

by Wernick, Pinner
& Sheasby

on AbeBooks

or eBay or


(affil links)

Being involved in all phases of anodizing from 1962 to 2006, until retirement -- plant design, engineering, technology, process development, such as Alcoa's 482 process ... all the anodizing process's. I have also been on panels with Arthur Brace, Sheasby, and Pinner. I have remembered only a very few times the word Alumite, that was nothing more than a trade mark or someone just using the name. I have been involved in bringing plants on line in several different countries. I was in charge of operations for Northrop Architectural Systems in the City of Industry, Ca for 16 years. If someone can shed more light on this name of Alumite I would like the information; it is not an anodizing process as we know it.

Zern Andersen, Ret
- Alpine California
May 15, 2017

A. Perhaps I should chime in to give my two cents.
I am a Japanese chemical engineer trained in U.S.
"Alumite" or "Almite" is a Japanese colloquial term for "anodized aluminum". It was "discovered" by Japanese scientists at RIKEN back in 1927. RIKEN was a part of a large conglomerate and seeking the way to capitalize their research efforts. "Almite" was one of the successful efforts and quickly spread through Japanese metal industries before and after WWII.
I remember the older Japanese chemists and metallurgists talked about this "discovery" as a first major achievement of Japanese scientists, beating the "western scientists" in the area of material science. Such a pride among older generation of engineers persisted well into 90's but these days, "yo-kyoku-sanka", which is more scientifically correct term, is used for "anodization" in general. However, Japanese wikipedia page for "anodizing" still has a title "almite".
As for the trademark, it has been long expired in Japan. I checked it on Japanese trademark database. Though "ALMITE" is now registered for some clothing brand or something.

I hope this helps.

- Kanagawa, Japan
September 7, 2017

December 16, 2019

A. This may shed some light for you all. I came across this while looking into coatings being applied to Japanese machine made swords and other military items a few years back.
It comes from a fellow Militaria collector and researcher - Nick Komiya. He is an older generation Japanese gentleman who is fluent in both reading and writing in both his own native Japanese as well as English. He has unearthed a wealth of important information from the Japanese Archives.

In a historically related article dealing with military canteens he writes:

(Previously)....I wrote how the army almost got a heart attack in 1901, when they discovered their aluminum bowls and plates crumbling due to corrosion. This was still the early days for aluminum and one does not hear about this problem now or even during WW2. Why?

That is because, in 1923 a Japanese company called Riken developed the world's first aluminum anodizing finish, using oxalic acid and patented it. This was called "Almite" in Japan since Riken trademarked that name in 1931. This was used on various household items like kettles, lunch boxes and plates, so when aluminum was specified, it was basically taken for granted that it would be Almite. The army naturally switched to Almite and that was how the corrosion problem could eventually be solved without having to specify anymore the location of pickled plums within the rice carried in the mess kit as did the early army manual.

The Chromic acid anodizing process developed in 1923 in England was also available in Japan, but was hardly applied to goods and was limited to duralumin aircraft components.

The sulfuric acid anodizing from the USA, which was discovered in the same year as well, also saw some application since around 1936, but was no match for the overwhelming popularity of Almite in Japan. However it did become more widespread as the war brought shortages of oxalic acid. They often had to tint it a brownish color to make it look like Almite for better acceptance by the population.

The army had Riken to thank for making aluminum the robust material it had become for field use, but when Riken tried to renew its patent in 1939 (patents were valid only for 15 years), citing that it's investment in two new large factories had not yet been fully amortized, the army prevailed upon its Minister to block this renewal. Riken's patent in those days restricted Almite processing to designated production facilities only and the army saw that as a very unwelcome bottleneck for expansion of its military production capacity, not to mention the extra cost of patent royalties to Riken.

Hope this helps some of you.

E Matak
- Melbourne, Victoria, Australia

January 2020

thumbs up sign  Very interesting, E, thanks!


pic of Ted Mooney
Ted Mooney, P.E. RET
Striving to live Aloha - Pine Beach, New Jersey

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