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Seagate's reported bid for TDK's head business would make Toshiba buy heads from a rival
Seagate is bidding against Toshiba for TDK's HDD head unit, the only independent head supplier, in a deal Bloomberg values at several billion dollars. Either winner would end that independence and could gain more say over what every drive maker pays for heads.
The Engineer · Build desk
What happened
- Toshiba approached TDK about the head business in spring 2026, and Seagate entered talks in the summer with a higher offer, according to people Bloomberg cited.
- TDK builds heads for each drive maker's newest recording method: HAMR for Seagate, EAMR for Western Digital and MAMR for Toshiba.
- Executives from Seagate, Toshiba and TDK reportedly met in Tokyo last week to discuss ways to keep head supply flowing, including a possible joint venture.
- Toshiba denied that the meeting took place and that it plans to buy head production, while Seagate and TDK declined to comment.
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Why it matters
- constraint Under a Seagate deal, Toshiba's planned HAMR drives would depend on head technology owned by a competitor whose own drives already use HAMR.
- exposure Storage buyers would face a head supply whose owner can sway pricing and slow how fast rival drive makers add output when demand jumps.
- contradiction Toshiba's denial means the two-bidder contest and the joint-venture talks rest for now on Bloomberg's unnamed sources alone.
TDK's head lines do two jobs in the HDD industry. Seagate and Western Digital build heads in-house and buy extra from TDK when demand outruns their own output [2]. Toshiba depends on TDK for all of its heads [1]. For Seagate, owning TDK's operation would add supply of a part it already makes [12]. A several-billion-dollar bid for a part Seagate already makes buys, above all, a customer list that includes both of its competitors [16][3].
A Toshiba win would give all three drive makers their own head production. Seagate and Western Digital would then lose their outside source of surge supply [14]. A Seagate win sends Western Digital's overflow orders to a Seagate-owned unit [15]. TrendForce estimates Seagate ships about 45% of HDD bits and Toshiba about 10% [10]. Add those, and heads from one company would sit inside roughly 55% of the bits the industry ships [13].
Toshiba's roadmap makes the dependence harder to unwind. Its next 30TB-class drives are expected to use MAS MAMR, and the models after them move to HAMR [4]. Tom's Hardware describes HAMR read and write heads as particularly hard and time-consuming to develop [5]. The publication expects Toshiba's current products are probably covered by long-term supply agreements. It calls TDK a key enabler for the roadmap generations as well [6].
TDK's reasons to sell hold whichever bidder wins. The head business is historically volatile and relatively low-margin, and it needs continuous investment as recording technology changes [9]. TDK has been moving resources toward batteries, passive components and sensors, expecting AI-related demand from devices such as smart glasses [9].
I think a joint venture is the outcome that best fits the problem. Bloomberg's sources say Seagate and Toshiba each worry about losing access to TDK heads if the other one wins [8]. Of the outcomes reported, only a shared structure avoids putting one drive maker in charge of another's heads [14]. Tom's Hardware expects any acquisition to face regulatory scrutiny because of the market's concentration and TDK's position in it [21]. The negotiations are preliminary and could end with no transaction [19].
What to watch
- Whether Toshiba keeps denying interest in TDK's head unit or confirms a bid against Seagate.
- Whether a joint-venture structure emerges that guarantees head supply to Toshiba and Western Digital.
- Antitrust review of any signed deal, given the market's concentration and TDK's position as the only independent head maker.