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.
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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.
Why it matters
- What it limits 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.
- Who's exposed 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.
- What doesn't add up contradiction Toshiba's denial means the two-bidder contest and the joint-venture talks rest for now on Bloomberg's unnamed sources alone.
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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 [1]. Toshiba depends on TDK for all of its heads [21]. For Seagate, owning TDK's operation would add supply of a part it already makes [14]. A several-billion-dollar bid for a part Seagate already makes buys, above all, a customer list that includes both of its competitors [18][7].
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 [15]. A Seagate win sends Western Digital's overflow orders to a Seagate-owned unit [17]. TrendForce estimates Seagate ships about 45% of HDD bits and Toshiba about 10% [6]. Add those, and heads from one company would sit inside roughly 55% of the bits the industry ships [16].
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 [8]. Tom's Hardware describes HAMR read and write heads as particularly hard and time-consuming to develop [9]. 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 [10].
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 [4]. TDK has been moving resources toward batteries, passive components and sensors, expecting AI-related demand from devices such as smart glasses [4].
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 [3]. Of the outcomes reported, only a shared structure avoids putting one drive maker in charge of another's heads [15]. Tom's Hardware expects any acquisition to face regulatory scrutiny because of the market's concentration and TDK's position in it [12]. The negotiations are preliminary and could end with no transaction [5].
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.
Clarity's read
What the record supports and how the coverage leans. The claims behind it follow.
Reality
- Evidence38
- Adoption
- Not scored
- Hype gap+20
- Incentives62
- Confidence40
Claim ledger
Ranked by verification strength, evidence, and original report placement.
- [1]
Seagate and Western Digital manufacture heads internally and also buy them from TDK when they need additional supply to respond to increases in demand.
- [2]
The successful bidder would control the industry's only independent head supplier, potentially giving it greater influence over pricing and making it more difficult for competitors to rapidly increase HDD output.
- [3]
Both Toshiba and Seagate are reportedly concerned about maintaining access to TDK heads if the rival bidder acquires the business.
- [4]
For TDK, a sale would exit a historically volatile, relatively low-margin business that requires continuous investment as recording technologies advance; TDK has been directing more resources toward batteries, passive components and sensors in anticipation of AI-related demand from devices such as smart glasses.
- [5]
The negotiations remain preliminary and could ultimately produce no transaction.
- [6]
TrendForce estimates that Seagate and Western Digital each account for approximately 45% of HDD shipments in terms of bits shipped, while Toshiba controls around 10%.
- [7]
TDK produces HDD heads for Seagate's HAMR drives, Western Digital's EAMR products and Toshiba's MAMR-based HDDs.
- [8]
Toshiba's next-generation 30TB-class HDDs are expected to rely on MAS MAMR technology, and their successors will rely on HAMR.
- [9]
Developing write and read heads for HAMR is particularly hard and time-consuming.
- [10]
TDK is a key enabler for Toshiba's HDD business both for existing products, for which Toshiba probably has long-term supply agreements, and for future generations that exist only on the roadmap.
- [11]
Seagate and TDK reportedly declined to comment on the Bloomberg report; Toshiba denied that any meeting took place and denied plans to acquire HDD head production capability.
- [12]
Any acquisition would likely face regulatory scrutiny because of the concentrated nature of the HDD market and TDK's unique position in it.
- [13]
If Seagate buys TDK's HDD heads operation, Toshiba's HDD business will depend on supply from Seagate.
- [14]
For Seagate, the acquisition would expand the supply of HDD heads that it also produces internally.
- [15]
Whichever bidder wins, TDK stops being an independent head supplier; a Toshiba win would give all three drive makers in-house head production and leave Seagate and Western Digital without an outside source of surge supply.
- [16]
Under Seagate ownership of TDK's head business, heads from Seagate-controlled production would supply drives accounting for roughly 55% of HDD bits shipped.
- [17]
If Seagate acquired TDK's head business, Western Digital's overflow head purchases from TDK would be bought from a Seagate-owned unit.
- [18]
Seagate Technology and Toshiba are reportedly competing to acquire TDK's hard disk drive magnetic head business in a transaction valued at several billion dollars, according to Bloomberg.
- [19]
Toshiba reportedly approached TDK about acquiring its HDD head operation in spring 2026; Seagate subsequently entered negotiations in summer with a higher offer, according to people familiar with the discussions.
- [20]
Executives from Seagate, Toshiba and TDK reportedly met in Tokyo last week to discuss mechanisms that could preserve supplies of magnetic heads, including a possible joint venture.
- [21]
TDK is the world's only independent supplier of HDD magnetic heads and Toshiba's sole source of the components; Toshiba depends entirely on TDK for them.
Sources
2 independent publishers whose own reporting we read for this story.
- techspot.comSeagate and Toshiba are reportedly fighting to acquire TDK's HDD magnetic-head technology
1 article · October 7, 2026
- tomshardware.comSeagate and Toshiba battle for TDK's HDD head business, a critical hard drive component
1 article · October 7, 2026
Topics and entities
Topics
- Hard disk drives
- Mergers and Acquisitions
- Storage component supply chain
Entities
- TrendForce
- Heat-assisted magnetic recording
- Bloomberg
- Western Digital
- Seagate Technology
- Toshiba
- Microwave-Assisted Magnetic Recording