TL;DR · 30-second read
The Short Version
Hard drives store much of the data behind today’s internet and AI services. Each one depends on a tiny part called the head, which reads and writes data as the disk spins.
Seagate, one of the world’s biggest hard-drive makers, is reportedly in talks with rival Toshiba to buy that business from TDK, a Japanese electronics company, and divide it between them.
Why it matters: about nine of every ten units of storage Seagate ships go into big data-center drives, demand it links to artificial intelligence. Owning the parts helps make sure it can deliver.
Simply Wall St reported on October 17, 2026 that Seagate Technology Holdings (Nasdaq: STX) is in talks with Toshiba to acquire TDK’s hard disk drive (HDD) magnetic head business. Under the reported structure, TDK’s head operations would be split between Seagate and Toshiba, concentrating a key drive component with two major drive manufacturers.
The talks are framed around securing HDD component supply as artificial intelligence workloads increase demand for high-capacity storage. No price, deal structure, financing or timeline has been disclosed, and none of the three companies has announced an agreement.
Executive Summary
Seagate is reportedly negotiating, jointly with Toshiba, to buy TDK’s business making the magnetic heads that read and write data on hard drive platters. The head is one of a drive’s most precise and critical components: every disk surface needs one, so every drive Seagate ships carries a fixed requirement for heads.
The timing reflects how Seagate’s business has shifted. AI-driven nearline demand, meaning high-capacity drives that stay online in data centers, now accounts for about 90% of Seagate’s exabyte shipments, and the company’s long-term build-to-order contracts stretch through 2028 and into 2029. When demand is already booked years out, the main risk moves from finding customers to delivering on time, and component supply becomes something worth owning rather than simply buying.
If completed, the deal would also narrow the independent supply base for HDD heads, placing TDK’s capacity inside two of the three remaining hard drive makers. That has implications for competitors, for cloud and AI buyers negotiating storage contracts, and potentially for competition regulators.
Ninety Percent Nearline Turns Head Supply Into a Delivery Risk
About 90% of Seagate’s exabyte shipments now go to AI-driven nearline demand. An exabyte is a billion gigabytes, and nearline drives are the high-capacity hard drives that cloud and AI operators install by the rack to hold large data sets that must stay accessible. Each of these drives stacks several platters and needs a head for every platter surface, so every exabyte Seagate commits to ship carries a built-in requirement for heads. As capacity per drive rises, so does the precision demanded of each head.
That requirement matters more because the demand is contracted. Seagate’s long-term build-to-order contracts reach through 2028 and into 2029. With volume already booked, the binding question is not whether customers will buy but whether Seagate can deliver, and any component it does not control is a point where another company’s capacity decisions, pricing or priorities can limit fulfilment. Owning part of a head supplier converts that external dependency into an internal capacity plan. This is the mechanism behind buying a supplier rather than only scaling output: added drive-assembly capacity is of limited use if the heads that go into each drive are allocated by someone else.
Seagate’s technology roadmap raises the stakes. Its Mozaic platform uses heat-assisted magnetic recording (HAMR), in which a tiny laser on the head briefly heats a spot on the disk so data can be written more densely. That makes the head a more complex part to manufacture at volume, and assured access to heads is a practical way to support the Mozaic capacity ramp. The parties most directly affected are Seagate’s contracted cloud and AI customers, who benefit if delivery becomes more certain, and Seagate’s rivals, whose position depends on where TDK’s capacity ends up.
A Split Purchase Narrows the Independent Supply Base
The reported structure divides TDK’s head operations between Seagate and Toshiba. The hard drive market has consolidated to three manufacturers: Seagate, Western Digital and Toshiba. A component capability that today sits with an independent supplier would move inside two of those three. For Toshiba, sharing the purchase is a way to secure supply without carrying the full cost; for Seagate, which has long produced many of its own heads, a share of TDK’s operations would add capacity alongside its existing production.
The open question is how the arrangement affects anyone outside it. Western Digital would be the only major drive maker not party to the deal, and neither Seagate nor Toshiba has said whether TDK’s head output currently serves other customers or what would happen to existing supply agreements. For storage buyers, a more vertically integrated supply chain can mean steadier allocations on contracted volume, but it can also reduce their ability to play independent suppliers against one another.
A transaction that concentrates a critical component among two of three manufacturers in a mature industry would likely draw review from competition authorities in multiple jurisdictions. No filing, approval process or timeline has been disclosed, so the regulatory path remains one of the larger unknowns.
Supply Assurance and Pricing Discipline Are Related, Not Identical
Seagate’s recent performance has rested partly on supply discipline that supports a higher price per exabyte. Control over more of the head supply chain makes that discipline easier to sustain, because decisions about how much capacity enters the market would sit more firmly with drive makers rather than component vendors. The two goals are compatible, but they serve different parties: assured supply primarily helps customers get what they contracted for, while disciplined capacity primarily helps margins. Buyers evaluating multi-year storage contracts should weigh both.
The supply-assurance case is coherent and consistent with where Seagate’s demand comes from, but it is not yet quantified. The clearest test will be whether Seagate begins disclosing how much of its HAMR-based nearline output and its contracted 2028 to 2029 volumes depend on in-house or jointly controlled heads. If that share proves large, the deal locks in an existing plan; if outside sourcing turns out to be minor, the strategic rationale would rest more on future capacity than present risk.
Background
Seagate Technology Holdings is a US-based data storage company that makes hard drives and related technologies, with customers in Singapore, the United States, the Netherlands and other regions. After decades of consolidation, it is one of three major hard drive manufacturers alongside Western Digital and Toshiba. Its business has shifted heavily toward high-capacity nearline drives for data centers, and it is ramping Mozaic, its platform based on heat-assisted magnetic recording (HAMR), to raise the capacity of each drive.
TDK is a Japanese electronic components company whose businesses include magnetic heads for hard disk drives. Heads are among the most technically demanding parts of a drive, and control over their supply has long been a strategic question for drive makers, a question that becomes sharper when demand is contracted years in advance. Source: Seagate Technology Holdings (STX) Is Exploring A HDD Head Acquisition (Simply Wall St, October 17, 2026): report that Seagate is in talks with Toshiba to acquire and split TDK’s HDD magnetic head business. See also Seagate Technology Holdings (STX) Eyes TDK HDD Head Deal As AI Storage Demand Builds (Yahoo Finance).Sources