KNOWLEDGE: Kobe Seiko wheels and history

Vintage Japanese works and aftermarket wheels are usually sought-after collectable items in the “JDM” or “Kyusha” community, and well documented. Websites like kyusha shoes show a lot of information, like available sizes, specifications, and old catalogue pages. Many people try to obtain these wheels to put them on their cars or on display. The rarer, the better. Some of these wheel manufacturers do still exist today and have started to re-issue vintage models for classic car owners. Despite all the hype, one name has remained largely under the radar of the collectors and fans: Kobe Seiko. Time to shed some light on the company, their history, their wheels, and specifically, the link to Nissan as an OEM supplier of their S30 Fairlady Z / Datsun 240Z Magnesium “Rally” and “sports option” wheels.

Disclaimer
As with all my knowledge articles, I tried my very best to get all information from trustworthy and official sources. However, I cannot guarantee that all information is 100% correct. If you have any correction, input or additional information, I appreciate if you let me know. I’ll update this post whenever I find something to add or change. I am not a professional journalist, but I put countless unpaid hours of work and years of research into this post and spent quite a bit of money to source a lot of original factory documentation, so please ask, before you copy anything. Thank you.

1. Kobe Seiko Company history
1.1 General Company history
Without diving too deep into the extensive and diverse history of Kobe Steel works, let’s take a quick look at the most important milestones.
In 1905, the general trading company Suzuki Shoten acquired a steel business in Wakinohama, Kobe, called Kobayashi Seikosho, operated by Seiichiro Kobayashi, and changed its name to Kobe Seikosho.
In 1911, Suzuki Shoten spun off the company to establish Kobe Steel Works, Ltd. at Wakinohamacho, Kobe, not far from Japan’s oldest known blacksmithing town, Mikki city.
The following photo shows their factory in Kobe in 1911, where they still operate a plant to this day.

Already in 1905, they started to produce forged and cast steel products, with one of their very first products being cast iron wheels for agricultural trolleys. For e.g. to transport sweet potatoes. The quality of their wheels was so immature and with many “bubbles” in the metal that they were referred to as “castella steel”, named after a sponge cake.

Despite several historical setbacks, like various fires, the great Kanto earthquake and World War II, which all destroyed large parts of their plants, the company managed to come back multiple times and grow into the largest and technologically most advanced steel manufacturer in Japan, with plants all over the country and even abroad – often being ahead of the competition. For e.g. by having the first blast furnace or an 8’000 ton free flow forging press (see following photo) in Japan. With their rapidly growing know-how, expertise and machinery, they became an important pillar to industrialize Japan, help the country with its war efforts, and after WWII rebuild the country and help Japan to become the modern industrial powerhouse it is known for today.

From the mid-20iest century, KS began to diversify their product range and produce everything from any kind of raw steel products, construction materials, Railway tracks, cement mixing machines, Piano wires, welding rods, ship hulls and propellers, bridge steel ropes, military helmets, steel wires, cooking pots, complete fertilizer plants, nails, sheet metals, entire tanks and heavy construction machinery, to Japans very first diesel engine (A licensed product of Swiss Sulzer AG) and aluminum beverage cans. If you’ve ever drank a cold Japanese Kirin Ichiban beer, chances are high you got in touch with some Kobe Metal.

Once average people started to be able to afford a personal car, the automotive business in Japan took off and became an important sector for Kobe Steel, where they manufactured and supplied many crucial raw materials and parts for the industry:
– Sheet metal for body panel and chassis production
– High tension steel wires for valve and suspension springs
– Forged crank shafts
– Welding consumables and welding robots for assembly lines
and much more. At some point, they even made tires, as the photo of a tire pressing and curing machine at Kobe Seiko (1957) shows:

Today, under the name of KOBELCO, it has become a typical Japanese industrial conglomerate where steel production is only a fraction of their business, with other sectors being “advanced materials”, welding, machinery, engineering, construction machinery, electric power plants and semiconductor machinery and products. Recently they became internationally famous for a scandal with falsified material certificates that were supplied to various big customers like Boeing and Toyota.
I’ve uploaded a 100 years history video from an anniversary DVD which they released, on YouTube, if you’d like to know more about their history (switch on subtitles to translate it to English).

Some Trivia:
– The former Japanese Prime Minister Shinzo Abe worked at Kobe steel ltd., before moving to politics
– KS is the owner and main sponsor of the Japanese Kobe steelers rugby team

1.2. Logo Evolution
From 1905 they used a Diamond shaped logo with an “S” inside. It stood for “Steel”, “Suzuki Shoten” and “Sugar”, as a sugar refining was another important business sector of Suzuki Shoten.
Once KS separated from Suzuki Shoten and started to sell machinery tools in 1911, they applied for the same logo, but a similar one had already been registered by another company, so they added the “swords” at each corner of the diamond as a trademark in 1911 and used it as an official company emblem from 1937.

After WWII there was a trend to reject western letters in Japan, and the company fulfilled the request of their employees to remove the letter “S” from the company logo, and replaced it with the Japanese “rising sun” flag, which is still used with the sworded diamond-shape logo until today:

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2. Light alloy division and the Nagoya plant
2.1. Light alloy division history
In February 1912, against the backdrop of increasing demand for aircraft, the company expanded into Nagoya, the center of the Japanese aircraft industry, to dramatically increase production of light alloy castings at it’s new Moji factory and began production of magnesium and aluminum alloy castings the same year.

In June 1913, a second forging plant was established, based on the requests of the Japanese Air Force and further operations began early 1917 after the outbreak of the WW1. The same year a large forging plant exlusively for the Japanese Navy was built. In 1918, as the war expanded, a new plant for lightweight aluminum alloy casting was built 400m north of the existing factory.  The Nogoya factory increased from 560 employees and 36’000 square meters to 330’000 square meters and 7’000 employees by 1920 and was an important large-scale aircraft parts manufacturer.

In 1937, a dedicated Kobe Seiko lightweight alloy division was established in Nagoya synergizing the individual local KS plants into one big specialized division, with the aim to further strengthen the supply of the local aviation industry.
This is the organization chart from 1974

2.2. The Nagoya plant
With the new established division, a new factory for light alloy forging and casting technology for high quality aircraft parts was established in Nagoya as well. This was done by separating the magnesium alloy casting division from the Moji Plant and the aluminum alloy forging division from the Kobe Plant. They started to develop lightweight aluminum and magnesium alloys, production processes and products, mainly for catering the local aircraft factories.
Photo of the new Nagoya plant 1937:

During WWII, the company basically got seized by the Japanese Military under the “military-mobilization-act” and cranked up production of airplane parts production for the Airforce massively.
It is said that KS was an important parts supplier for Mitsubishi Aircraft Works with it’s A6M “Zero fighter” airplane, but I could not find any official confirmation to prove it.
De-Go observation aircraft, built by Kobe Seiko, commissioned by the Royal Japanese Army (Around 1943):

During the “Great Nagoya air raids” of WWII in May 1945, more than half of the buildings and equipment got destroyed and could not be rebuilt before the war ended.

After the war, the company shifted to civilian goods and in February 1946, Kobe Seiko received the permission to reopen business at the factory that was not war-damaged and began producing cast and forged parts for Bicycles, Motorcycles and Automobiles and electrical equipment. From November 1946 they started to steadily expand their business 0f automotive, cast iron and die-casting parts. In 1955, with the resurgence of domestic aircraft producton, the plant resumed the production of aircraft parts.

Later, when the “Kobe steel Metal industries” got established, and the Chofu and Moji plants got integrated there, the Nagoya Plant remained as forging and casting division, because of their unique and deep knowledge, experience and skills in that sector. In 1965 the Nagoya plant rejoined the Lightwight Rolled steel division and and aside from casting and forging also produced stamped rolled steel products, like refridgirator tanks, and became the central hub for lightwight metal products.

In 1965, a specialized research laboratory was established and and the plant has since then expanded its activities to reduce weight, increase strength and reduce costs for aircraft, defense and civilian products.
The production methods range from sand casting, lost-wax plaster molding, metal molds and seamless casting to die-casting. In 1952 low pressure automotive aluminum rim casting got introduced and in 1986 precision sand mold casting. Computer solidification analysis was introduced in 1959 and composite mold casting in 1960.

The Nagoya plant 1974:

2.3. Kobe Steel as an alloy wheel manufacturer
In 1942, with the increasing demand for automotive products, they started to manufacture lightweight alloy wheels (Magnesium and Aluminum) in their light alloy division at the Nagoya plant, an important product for their rapidly growing US-export market. Shortly thereafter, the domestic needs for light alloy wheels started to increase as well, so in 1954, the company started construction to increase the production capacity to a staggering 55’000 Automotive alloy rims per month!!
Nissan “Iron Cross” aluminum rims production at the Kobe Seiko Nagoya plant in the early 80ies:

Following the oil crisis, the business division began consolidating and rationalizing its production from 1978 to 1982 with the aim to improve its competitiveness. The company increased aluminum wheel production and introduced new 1’500 and 8’000 ton forging presses, and advanced inspection equipment and established systems for producing larger and more precise products at higher quality. From 1985 they further increased their precision machining capacities and used computer aided systems under the slogan of “build a Nagoya factory capable of responding to cutting-edge technology industries“, with the aim to set foot in the fast-growing semiconductor business.

In 1992 the new “Daian” Plan was built and from 1993 to 1995 all operations were transferred to that new location, as one centralized factory for all “advanced materials”.

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3. Wheels
3.1. Nissan / Datsun OEM wheels supplier
Kobe Seiko most probably already supplied other metal materials for Nissan (spring wires, sheet metal, etc.) and they were probably the only ones able to process lightweight Magnesium with automotive quality standards at that time, so I like to think they were not only a natural, but also the only choice that Nissan had, back in the days to get their Magnesium wheels in large quantities, and from that, a long-term partnership evolved that included many Aluminum wheels.
I’m pretty sure that most (if not all) Nissan branded aluminum / magnesium OEM or optional wheels that Nissan / Datsun sold in the late 70ies and 80ies were made by Kobe Seiko. The following picture shows an excerpt of a Datsun USA optional wheel flyer and if you look closely you can see the Kobe Seiko Logo casting mark in some of the wheels (see red mark. On the other wheels, the mark was on the backside). Note the wheel in the center, shown on the 280Z;

Nissan / Datusn S130 wheels
In the early 80ies, when Aluminum wheels became a more popular choice, Nissan introduced many (optional) Aluminum wheel designs for the S130 and other cars. One is the “Iron cross” wheel shown below (Thanks Jeff!).
Note. See photo above of these “Iron Cross” wheels in the making at the Kobe Seiko factory!

A good overview of other available factory alloy wheels for the S130 is also shown here: https://xenonzcar.com/s130/wheeldifferences.html. I’m pretty sure they’re all made by Kobe Seiko.

I’m also pretty sure that Nissan sold many other KS-made wheels at that time for other cars.
For e.g.  here you can see an overview of option wheels for the Datsun / Nissan Sunny:
http://datsun1200.com/modules/mediawiki/index.php?title=Datsun_Option_Wheels

3.2. Nissan Z432 & Datsun 240Z “Portugal spec” Magnesium Wheels (-E4200)
The Nissan S30 Fairlady Z and Datsun 240Z / 260Z / 280Z came from the factory with steel wheels by TOPY, another Japanese wheel manufacturer. In the mid / late 70ies, optional Alumium wheels became available from Nissan for those cars, but the Japanese-market-only Nissan Fairlady Z432 plus the special Portuguese market Datsun 240Z came with Kobe-Seiko made Magnesium wheels from the factory, straight from the beginning.
Those 40300-E4200 in the now-iconic design, are made from magnesium alloy (not pure magnesium), have a  5,5Jx14″ size and weight about 6kg each. Note the raised center with three holes for the installation of the Center cap and the closed holes in the smaller gaps between the spokes.  Also note the special paint color listed for those wheels.

1969 Japanese market Fairlady Z432 with factory Magnesium wheels, from the Nissan Heritage collection. Note the black center cap for Japanese market.

The Portugal spec cars got the same wheels with a special Datsun “D” Center cap. I’m not sure if the wheel color is original or if it’s just unpainted, but you can clearly see the “D” Center cap. In the third photo, you can see an original Japanese market Center cap on the left and four reproductions on the right.

In some of the development crash test video footage, you can see those wheels being tested on LHD cars with the “D” Center caps on it. In an Interview with Z432 and European-spec Z developer Michio Takei, he mentioned that the Z432 wheel was originally considered as the standard wheel for European export cars, but they had issues with chipping and even a reported fire-incident and customers didn’t know how to handle them properly, so they decided to not use them for the general European export market.

3.3 S30 Works Race “Rally Mag” wheels
The Kobe-seiko-made “Rally Mag” magnesium wheels where a slightly different version from the Z432 wheel. The ‘”Rally Mag” design was exclusively used by the Nissan Works teams (first for the Works Z432-R circuit racing cars and then for the Works rally cars) and were NOT offered to the general public with a part number or sale price, so they are not mentioned in the Sports/Race Option catalogues or the race and rally ‘yellow books’. Some may have ended up in works-supported privateer race teams.
The main difference to the standard Z432 wheel was their wider 7J x 14″ rim size, but there have been observations of a narrower version (looks like 6J) in very rare circumstances, used on the FRONT of the cars in snow and ice conditions. Also, the Rally Mag wheels didn’t have the raised center for the installation of a center cap and the smaller gaps between the spokes are open (holes) vs closed in the Z432 wheels. They therefore only weight about 5.4kg each, which is 600 grams lighter than the Z432 wheel, despite being 1,5inch wider.

1973 HLS30 Safari Rally winner (Photo courtesy of the Nissan Heritage website)

1972 Rally Monte Carlo Winner (Photo from the Nissan heritage collection)

A pile of Kobe Seiko Magnesium Works “Rally Mag” wheels at the 1972 Rally Monte Carlo (Nissan press Photo)

3.4 S30 Sport option “8-Spoke” wheels 
Additionally, there where “sport option” wheels sold by Nissan Sports corner (Japan) and the Datsun Competition department (USA) as optional parts to private racing teams and S30 owners.
The following excerpt from the Japanese S30 “Race and Rally preparation manual” shows an overview of the “Sport option” wheels including what specific lug nuts, etc. must be used and which cars the fit for.
Standard Z432 PS30 wheel (See also above): 5,5×14 – 40300-E4200
Specified as “road wheels” (for road racing) for the Z432-R (PS30-SB) and PGC10 Skyline:
8J x 14″ – 40300-E7200 (front and rear usage)
10J x 14″ – 43300-E7200 (Rear usage only)

Those -E720o wheels, available in 6Jx14″ and 10Jx14″ are again Magnesium Alloy wheels made by Kobe Seiko, exclusively for Nissan.
They usually come with a Date-stamp and the “Nissan Hamburger” mark:

In the January 1979 Japanese “Sports option” catalogue, all magnesium  (and steel) wheels are all already marked as “discontinued”:

S30 “4-Spoke” aka “Gotti style” wheels 
Another famous Nissan racing wheel design for the S30, are the Kobe-Seiko made Magnesium alloy rims often referred to as “Gotti style” because of the similar design, even if KS produced those wheels before Gotti released their wheels.
In the following gallery, you can see them worn on the famous 1973 GTS-II group race car replica. Note the “Hamburger mark” on the wheels:

 

They were very thin wall thickness on the rim section. Very light (A 10Jx15 version has a weight of about 5kg). For circuit use only. Here is a pair I saw for sale on Yahoo auctions recently, in 10Jx14″.

While the original H(L)S30 FIA Homologation only included the TOPY-made pressed steel wheels (in 4,5Jx14″ and 5,5Jx14″):

In a later FIA Homologation sheet version, you can see that 7, 8 and 10″ wide Magnesium wheels got added, too, while the 14″ diameter remained the same.

3.5. Kobe Seiko own aftermarket wheels
It’s probably safe to say that their main wheel-related business was as an OEM supplier for car manufacturers and the aftermarket, but with the increasing tuning-hype in the late 70ies and 80ies, Kobe Steel wanted to have their piece of the cake and released their own series of Kobe-Seiko branded aftermarket Aluminum and Magnesium wheels.
Orginal, period “Kobe Aluminum & Magnesium Wheel” sticker (Thanks Ian!):

The date stamps on the wheels show that the wheels were only ever produced over a short period in smaller batches.
I’m still trying to find a product-overwiew or general catalogue from the KS wheel lineup. At least, during my research, I found some ads and plenty of different styles of wheels – so let me post a small gallery for reference of each wheel I found. I’m pretty sure there were more, though:

Kobe Seiko “Magnesium” wheel:
Material: Magnesium
Known sizes: 5,5Jx13″ size with a 4×114,3 bolt pattern:
Known colors: Gold, Silver, Black (note: Two gold shades are both original, according to some sources, they changed the color at some point during the production period):
Note: Picture from my own collection of wheels:

Kobe Seiko “MagRoad” wheel:
A popoular 8-spoke design, similar to the RS-Watanabe or Panasports design, inspired by british racing wheels.
Material: Aluminum
Sizes: 5Jx13″ / 6Jx13″ / 6,5Jx13″ / 7Jx13″ / 6Jx14″ / 6,5Jx14″ / 7Jx14″ (See list in the ads in the gallery below to see all details)
Known colors: Gold, Silver, Black
Note: Color of wheels in the following gallery is not a factory color, but they have been repainted at some point:

 

Kobe Seiko “Eurotax” wheel:
I’m not entirely sure if the Name of the wheel is actually “Eurotax” or if that casting mark there for another reason, but it made me name them after that.
Material: Aluminum
Known sizes: 6Jx14″ with 4×114,3 Bolt pattern
Known colors: ?
Note: It appears that the white color is not an orginal one, so original colors remain unknown. The wheels we know about have a production date stamp of February 1978. Just before the Maglloys.

Kobe Seiko Unknown (“Enkei dish style”) wheels:
The name of the wheel is again unknown, so I named them after the similar Enkei Dish wheels. Many other similar wheels from different manufacturers were available at that time.
Material: Aluminum
Sizes: 6Jx14″, Offset 10 / 5,5Jx14″, 4×114,3 Bolt pattern
Known colors: ?
Note: –

Kobe Seiko Unknown (“Cross”) wheels:
Again, I don’t know the original name of these wheels, but due to it’s “cross” shaped 4-spoke design, I call them “Cross”, until the orignal name is found:
Material: Aluminum
Sizes: 5,5Jx14″, Offset 22, 4×114,3 Bolt pattern
Known colors: ?
Note: –

Kobe Seiko Unknown (“Star”) wheels:
Again, I don’t know the original name of these wheels, but due to it’s “Star” shaped design, I call them “Star”, until the orignal name is found:
Material: Aluminum
Sizes: 5,5Jx13″, Offset 22
Known colors: Silver (unpainted, with polished accents):
Note: –

Kobe Seiko Maglloy wheels:
The Maglloy where Kobe Seiko’s own interpretation of the Nissan Fairlady Z432 / Works Rally Magnesium wheels (see later in this story), which they made available for the public. It’s a popular choice for people who want to have a Z432 look, or do not want to use their rare original Magnesium wheels, while still using vintage Kob Seiko-made wheels. So they have become quite sought after and expensive and not too easy to find in correct sizes. The main differences to th Z432 / Rally mag wheels are the different sizes (6J wide vs. 5.5J (Z432)/ 7J (Rally)) and the special “Maglloy” Center cap which is mounted without a raised center, as seen on the Z432 wheels. Also note the closed smaller gaps between the spokes, similar to the Z432 wheels.
Material: Magnesium
Sizes: 6Jx13″, offset 20 / 6Jx14″, offset 20, with 4×114,3 Bolt pattern
Known colors: Silver, gold, “gunmetal” black.
Note: Thanks to Ian for the photos of the wheels! It appears that a raw-cast wheel made it out the backdoor and went for sale in JP with the “Maglloy” logo grinded off to resemble the rally Mag or Z432 wheels.

Here is another gallery with the rarely seen 13″ Maglloys, with beautiful markings. As you can see, both Maglloys shown here where produced around 1978

3.6. Kobe Seiko as Manufacturer for other aftermarket brands
Kobe Steel not only produced their own aftermarket wheels, but were also manufacturing wheels for other aftermarket brands.
In the following photos you can see two slightly different Hayashi “Street” Aluminum wheels wearing both the Hayashi AND the Kobe Seiko logo:

3.7. Other KS-made race car wheels
Nissan also sold / supplied Kobe-seiko-made lightweight alloy race and sport option wheels for other cars in their lineup during the 70ies and 80ies. for Private owners, to private race teams to Works-team-exclusive wheels. there were were a wide range of both similar and different design wheels available.

Rally mag wheels in different sizes
The KS Rally Mag’s Magnesium wheels also were used on other cars and came in different sizes. for e.g. this 14″ version on the Bluebird 610 (in the photos you can see that they came both in the Z432 look with raised cnter and closed gap and the Rally mag look with no center caps, but still with closed gap) 

The violet 710  version was a similar “rally mag” with closed spoke-gaps and no center caps, and came in 5,5Jx14″ size at a weight of about 5,4 kilograms. There might be other versions used on other Works rally cars as well.Note Production date stamps March 1972 and september 1971:

8-spokes in various sizes
The Kobe-Seiko 8-spoke design was a very common Sports option / race wheel on a variety of Nissan cars in one or another form. They were used in various sizes on everything from works Fairlady roadster’s to 610 bluebirds, to Hakosuka Skylines up to the orignal R380 (Front wheels only), as pure racing or “Sports option” wheels

Here is a set advertized as Sunny B110 / B310 Magnesium wheels with each two 8,5Jx13″ and 9,5Jx13″, which was for sale, recently:

 

4-Spoke Cherry “Works Mag” wheel
Another sought-after KS-made wheel is the Nissan Cherry Works Mag race wheel, as seen in 13″ on this 1973 Nissan Cherry Coupe X-1 KPE10

4-Spoke “Sunny” wheel.
Made in Aluminum, came in 8Jx14″ and 9Jx14″ and probably other sizes. Have the Nissan “Hamburger Mark” cast on one spoke.
Used on the Sunny B110 / B210 and probably also sold for other 4-cylinder cars as a sports option and racing wheel:

Another KS-made works Rally wheel which is often seen on the Violet Rally cars from the late 70ies / early 80ies. You will find plenty of similar designs from KS on other Nissan sports and race cars from that era:

Formula & group 7 race car rims:
Aside from their “sports option”, circuit racing and rally sports wheels, Kobe Seiko also made pure racing wheels for Formula type race cars, as the unknown one, shown below:

And they also produced the 5-spoke rims for the Nissan R381 / R382 / R383 group 7 race cars, as seen on this R382 (from 1969)

3.8. Z432 & Rally Mag wheel Replicas
Because the Z432 and “Rally mag” wheels have become a famous and rare, sought-after wheel for S30 / 240Z owners around the globe, who want to have the Z432 or Works rally car look, manufacturers started to make their own reproductions of the wheel. Some close to the original ones, most not. In fact the lastest versions you can see for sale are more of a copy-from-the-copy-from-the-copy-from-the-copy version and does not have too much in common with the original z432 or Rally Mag wheels. I think this deserves it’s own section of the story as there seems to be a lot of confusion:

Kobe seiko
KS introduced their own version of the “Z432” wheel, called the “Maglloy”, once the original wheels were obsolete. It is slightly different in sizes and design, different center caps, etc. Probably to avoid copyright issues.
Made around 1978. It’s made out of magnesium, by the same company that made the original Z432 and Rally wheels.
–> See previous chapters for photos and specification.

UK Made Replicas.
I won’t go into the details, but a big Z-enthusiast in the UK has taken the effort to make limited runs of sand-cas reproductions, based on actual original wheels. Both in Z432 and Rally sizes and design, and both in Aluminum and Megnesium alloys. These are probably the most accurate reproductions both from the design point of view, but also details like the rough surface, casting marks, etc. From what I was told, the production numbers were very low, and they were never intended for commercial scale sales, rather than a small batch made by enthusiats for enthusiasts.

Rose auto Z432 wheel replica
Rose Auto, in Kyoto JP sold a limited run of  Aluminum Z432 replica wheels in original 5,5Jx14″ specification with 25mm offset. Thes appear to be pretty close to the original Z432 wheels with the raised center and 3-screw centercap and closed small gap between the spokes. Despite the many casting marks on the back, I wasn’t able to see who was the manufacturer of those wheels.

Revive Jalopy Japan Rally Mag replica
A few years ago, the Japanese classic Nissan specialist Revive Jalopy made a limited run of “Rally Mag” wheels in the original 7Jx14″ sizes. But they were made in Aluminum instead of the original Magnesium alloy.
Note: No raised center for center cap mounts and open smaller gap between the spokes, just like the original rally mag wheels

M.speed Z432 and Rally Mag replicas
M.speed Japan also made a limited run of Aluminum reproduction wheels in both the 5,5Jx14″ Z432 style (Offset +25mm) and 7Jx14″ (Offset -16) Mag rallye style. The shape around the edges was slightly different than the original ones. Either it was their own interpretation or they wanted to avoid copyright issues. The wheels were manufactured in China, but tested by M.speed for durability, strength and quality in Japan by an authorized body, to get the JWL Mark.
Upper row: Z432 wheel (Some pictures courtesy of Ian)
Lower row: Rallye Wheel (Some pictures courtesy of JDM-Car-Parts)

Once owners in the USA and Europe became aware of such wheels and wanted to have them for their Z432 / Rally car replicas, other manufacturers started to copy the wheels too.

Chinese replicas
Now, after M.speed had those wheels made in China, the story gets wild. Some people figured out who the original manufacturing company was in China and asked them for the wheels too. The Chinese company would happily sell those exact same M-speed wheels through their backdoor, to whoever asked them, despite M.speed most probably holding the intellectual property rights on the design and also M.speed having the JWL test certificates for their products. Suddenly, the wheels appeared under a variety of brand names and channels, all from the same manufacturer. The wheels were both available in the Z432 and Rally spec sizes as from M.Speed, but on request from one of the later sellers also made available in new, upscaled 15″ sizes, which was never a factory Kobe Seiko size.

I don’t want to name any brands You find them on various Ebay, Facebook and other webshop sizes. All unauthorized reproductions by the shop who originally produced the M.Speed wheels, while M.Speed stlll owns their original design and the test documents for it. It appears that at least some resellers are aware of the backstory and have come up with adventurous excuses to not being able to supply those wheels, but I will not go deeper into that, as I don’t know the story of each shop that sells reproductions from that certain supplier.

Another strange example are the Chinese made YKW wheels (not to be confused with Canadian wheel manufacturer YKW). The design is obviously “inspired” by the KS rally wheels, but many things seem completely off.  The size is 8Jx15, but with a bolt pattern of 4×100, which means it doesn’t even fit on a classic Nissan. The ad says they’re made for Kei-cars.

Others:
Some people took the effort to make their own wheels, like ths guy named Harold Burroughs, who his own KS-replica wheels, CNC-milled 3-piece design from solid aluminum:

Sun Kang (of fast an furious fame). has made a very limited run of a wheel that is intended to pay a modern day hommage to the Z432 wheel for his own 240Z, while not having that much in common with the original wheel.

And then a company called Slipwell made a “Kobe Seiko Magnesium – Datsun Fairlady Z432” slipmat for your turntables.  But if you look closely, you can clearly see that it’s based on a photo of a Maglloy wheel and not a Z432.

4. Conclusion
While Kobe Steel aka Kobe Seiko is mainly known for making the Z432 and S30 Works rally wheels, it’s safe to say they were much bigger and made way more wheels then most would think. They were a major OEM supplier for Nissan and important manufacturer of wheels for other companies without the machinery to produce alloy wheels themselves, and have played an important role in the 70ies and 80ies as an industrial-scale producer of alloy wheels with unique knowhow, facilities and long-standing experience. While all the other big brands get the fame for making cool aftermarket wheels in that era, I’m confident that most other wheel manufacturers didn’t have such a long-standing history in alloy production, nor the massive laboratories and RnD capabilities that Kobe Seiko had. It’s about time the story about them gets heard and their wheels get the recognition they deserve, especially outside the S30 owners bubble.
Despite the original Kobe Seiko Z432 and Rally wheels being rare and sought-after by enthusiasts, the majority of S30 owners have probably never heard of them, and of those who know them. the majority prefers to put other style aftermarket wheels on them. So it’s kind if hilarious to see how many manufacturers now sell copies of the copies of the copies of those original KS wheels, while original Japanese ones or early, legit japanese market reproductions still pop up for sale regularly, and while the market for these wheels is still a really small niche.

5. Ressources:
While, honestly I forgot where some of the photos, which I’ve collected over the years, came from, many of the published information and photos came directly from the Kobe Steel anniversary chronicle books shown below, and other Nissan / Kobe Seiko information, adveretizement from early motorsports magazines and the publsihed history videos and the KOBELCO website itself.
Btw: That wooden crate is a vintage Kobe Steel Welding rod crate, which I use to display one of my Kobe Seiko Magnesium wheels.

Other useful links for further information:
Wikipedia website: https://en.wikipedia.org/wiki/Kobe_Steel
Kobelco advanced materials division History: https://www.kobelco.co.jp/english/products/advanced-materials/about-almi/history.html 
120 year anniversary animation 2025: https://www.youtube.com/watch?v=o0wx52IybE0

Thank you
Special thanks go out to Ian, Alan, Gavin, Jeff, Chris, Flo and everybody else who, once again, provided very useful information, helped me identify certain wheels and supplied many of the photos for this story!