A processing site closes, but customer supply is supposed to continue

On October 28, 2026, Mitsubishi Materials said it would stop slitting and sales of copper and copper-alloy strips at Ryoshindo Manufacturing (RM) in Johor, Malaysia, in March 2027. RM was established in 1995 and has served Southeast Asian customers.

However, Mitsubishi Materials also specified a future supply arrangement: the products will continue to be supplied from its Wakamatsu Plant in Aizuwakamatsu, Fukushima Prefecture. The local processing function is being discontinued, while supply to customers is intended to continue.

The announcement covers those specific operations. It does not establish that the entire Malaysian legal entity will be dissolved or that all local commercial activity will end. The difference matters when assessing what the group is actually giving up.

What makes processing close to the customer worth its capital?

Slitting converts a coil of copper or copper-alloy strip into customer-specific widths. Keeping that capability near electronics or automotive component manufacturers can support shorter response times and changing specifications.

But a local processing site also requires equipment, operators, quality control and stock of raw and converted material. Depending on volume and product variety, the working capital and duplicated assets may outweigh the customer service advantage. Mitsubishi Materials did not disclose RM's exact utilization or site economics.

The company said it expects to improve production efficiency and capital efficiency by reducing inventory. The managerial question is not whether local slitting can be done, but whether its benefits still justify keeping it in Johor.

Scrap export rules are a factor, not a complete explanation

Management cited changes in market and competitive conditions as well as tightened Malaysian scrap-export restrictions. Copper scrap generated during processing can be recovered and reused as valuable metal input, making resource circulation part of the supply network.

Yet the release does not quantify scrap volumes, historical cross-border flows or additional cost caused by a specific restriction. It would overstate the evidence to say one regulation forced the shutdown of an entire factory.

What is confirmed is a broader reassessment of supply, recycling, processing and logistics. This is a decision about the whole operating arrangement rather than one isolated regulation.

Centralizing supply in Japan may reduce inventory—or relocate it

Concentrating processing in fewer locations can reduce duplicated stocks and improve utilization. Releasing cash previously tied up in raw and finished material can improve working-capital efficiency even without additional sales.

Yet supplying Southeast Asia from Fukushima may increase freight costs or transport time. To preserve service levels, the company might need buffer inventory closer to customers. A decline in RM's stock alone would not prove the entire supply chain is holding less.

New freight arrangements, customer-specific lead times, net inventory savings and cost changes have not been disclosed. Those will be the measures that determine whether the planned supply transition is successful.

Japan's separate bar-product exit has a different supply solution

In June, Mitsubishi Materials announced plans to stop manufacturing certain copper bars, copper-alloy bars, special brass products and ECO BRASS forged products in Japan by November 2027, with sales ending in March 2028. These are different products from the Malaysian strip slitting operation.

An August announcement detailed a technical-assistance agreement with KITZ Metal Works, signed July 31, to support production of selected products such as ECO BRASS and particular copper bars at KITZ. Other products may be handled through group-company transfers or substitute offers.

The approaches differ: Malaysia's affected supply shifts to another company-owned plant, while selected Japanese bar products are to be supported through an outside manufacturing partner. Stopping in-house manufacturing and ending every means of supplying customers are not the same decision.

The same group is expanding a Thai product line sixfold

Five days earlier, on October 23, Mitsubishi Materials announced a phased expansion of VH-series flake thermistor production at MMC Electronics Thailand in Samut Prakan. The target is around 12 million units a month by November 2027—roughly six times the 2025 capacity.

These small temperature sensors help optical transceivers operate reliably. Mitsubishi Materials attributes the expansion to growing optical communications demand as generative AI becomes more widespread.

The Thai investment is a different product and technology from copper-strip slitting in Malaysia. There is no evidence of a direct transfer of savings from Johor into Thai thermistors. Nonetheless, the contrasting decisions show why groups may withdraw capital from one function and expand capacity in another.

Which capabilities must a manufacturer own?

Mitsubishi Materials says the Malaysian restructuring should release resources for growth fields such as high-performance copper alloys, xEV materials and data-center materials. That is an announced intention, not a demonstrated profit contribution.

Management can keep a process within one owned plant, consolidate production at another group site, or provide technology for an external partner to manufacture selected products. The right arrangement depends on required specifications, qualifications, know-how, capital intensity and customer risk.

The Malaysia, KITZ and Thai decisions are separate. Treating all three as a single reshoring campaign or a direct capital transfer would erase the important difference between product portfolios and functions.

What should customers and investors verify after the transition?

The company expects the impact on fiscal 2026 consolidated financial results to be immaterial. The disclosed facts are the scheduled end of operations and the intended continuation of supply—not achieved savings.

Customers should check whether delivery lead times, product quality and availability remain stable. Management should evaluate total freight, inventory and working capital across the network, not just the cost of one plant.

The lasting question is which manufacturing functions justify being locally owned. The success of the restructuring can be judged only after the new supply arrangement operates and those outcomes can be measured.

BANSEOG VIEW

BANSEOG VIEW | Ending local processing is not necessarily a market exit

The Malaysian decision is scoped to copper-strip slitting and sales at RM; product supply is intended to continue from Wakamatsu. Neither a full subsidiary closure nor the end of every Malaysian customer relationship is established.

The separate Japanese bar-product exit, KITZ technical assistance and Thai thermistor expansion show different manufacturing options, not a proven direct transfer of investment across these products.

The claimed improvement in capital efficiency needs to be verified through customer lead times, quality, total inventory and freight costs. The intended reallocation is not yet a realized result.

SOURCES

Primary sources and references

Prepared Oct 29, 2026. Oct 28 Malaysian RM (founded 1995, Johor) announcement concerns cessation of copper-strip slitting and sales in March 2027 and continued supply from Wakamatsu. Market and competition changes and tighter scrap-export rules are cited but not quantified. June 12 Japanese bar/ECO BRASS exit (manufacturing Nov 2027, sales Mar 2028) and Aug 6 KITZ technical assistance (contract executed Jul 31) concern different products. Oct 23 Thai VH thermistor sixfold capacity expansion by Nov 2027 is another product. Site-wide subsidiary closure, employee impacts, direct reallocation of funding, actual inventory benefits or delivery outcomes are not disclosed.