Among the most exposed are car and parts makers such as Toyota Motor Corp. and Denso Corp.. Domestic carmakers get about 70% of their aluminium imports from the Middle East, according to the nation’s top auto lobby. The price of the lightweight alloy — used in everything from engine parts to wheels — has risen by about 13% since hostilities began in late February.
“It’s only been a month but it’s almost certain that we’ll soon have trouble making automobile parts,” Daiki Kato, chief executive officer of Kato Light Metal Industry Co., said in an interview in late March. “We’re going to spend more selectively and conserve our energy.”
With the Middle East’s top aluminium producer predicting it would take at least a year to restore full production, Japan is at the forefront of what may spiral into a prolonged global shortage of the metal. Analysts at JPMorgan Chase & Co. warned last week that the industry had entered a “black hole” it will not easily emerge from. Even if a peace deal is reached and the vital Strait of Hormuz reopens, it could still take months for shipping to return to normal levels.
Japan imported around 590,000 tonnes of aluminium, or about 30% of its total supply, from the Middle East in 2025, according to the Japan Aluminum Association. The United States imports more aluminium than Japan, but US companies are not in danger of running out because they source most of their supply domestically and from Canada, according to Bloomberg Intelligence.
Japan is the most vulnerable country to aluminium shortages, according to S&P Global Inc. analyst Masatoshi Nishimoto. Southeast Asia, China and South Korea are also among the nations facing “the greatest risk”, he said.
Not only has the war reduced shipping through the Strait of Hormuz, but key aluminium refineries in Abu Dhabi and Bahrain were damaged in the early stages of the conflict as Iran attacked regional neighbours in response to US and Israeli assaults.
One company feeling the impact is Kato Light Metal. Based in Aichi Prefecture, the firm makes a variety of aluminium products, mostly for construction and automobiles.
It imports about 400 tonnes of aluminium every month — roughly 200 tonnes each from Dubai and Australia. While deliveries from the Middle East have stopped, the company said it has enough inventory to last until May. Beyond that, it plans to buy aluminium from a supplier in Southeast Asia.
Elsewhere, Toyota supplier Denso and its affiliates have had to reduce monthly output by around 20,000 units, the company said in late March, resulting in sizeable losses.
Supply constraints from the region could persist for months even if the war ends, as refineries take time to come back online and shipping companies work to clear a backlog of hundreds of ships stuck in the Persian Gulf.
Most companies in Japan typically maintain about two months of inventory for parts or raw materials. This means many could begin to face disruptions by the end of this month or early May.
Spokespeople for Toyota declined to comment on aluminium or impending supply shortages, but said they are monitoring the situation. Nissan Motor Co. said it is “taking appropriate measures, including adjustments to our production and logistics operations”.
“The conflict is beginning to affect deliveries and supplies,” said Koji Sato, chair of the Japan Automobile Manufacturers Association and Toyota’s former chief executive officer.
Aluminium is the most commonly used metal after steel. Lighter and better at dissipating heat, it is a key component in engine parts such as pistons and cylinder heads, as well as body panels and alloy wheels. It is also used in everything from electronics and building materials to beverage cans and snack packaging.
The disruption to supplies could lead companies to run out of certain specialised products, forcing factories into temporary shutdowns. The longer the war continues, the longer supply chains will take to recover, increasing the risk that production could grind to a halt.
“Manufacturers are starting to seek out alternatives as their inventories begin to run dry,” said Koji Iida of the Japan Aluminum Association. “It’s an extremely difficult situation and concerns are high among small and medium-sized companies.”
