# Humanoid Gear Makers Are Building for 714,000 Robots a Year. IFR Counted 7,000.

> Markdown twin of https://roboterminal.app/posts/harmonic-reducer-capacity-vs-humanoids · https://roboterminal.app/posts/harmonic-reducer-capacity-vs-humanoids.md

**Published:** 2026-10-09

Main Drive's late-2027 plan of 10 million harmonic reducers a year would cover about 714,000 humanoids at 14 per robot, against about 7,000 full-size humanoids IFR counted sold in 2025.

Taiwan's Main Drive plans up to 10 million harmonic reducers a year by late 2027, while China's Leaderdrive and Laifual target a combined 2.16 million run rate by the end of 2026 and prices keep falling. The joint that was supposed to bottleneck humanoids is turning into a commodity. The scarce parts now are steel, process, and signed orders.

**Companies:** [Mirle Automation](https://roboterminal.app/companies/mirle-automation), [Main Drive](https://roboterminal.app/companies/main-drive), [Leaderdrive](https://roboterminal.app/companies/leader-drive), [Laifual](https://roboterminal.app/companies/laifual), [Schaeffler](https://roboterminal.app/companies/schaeffler), [Nabtesco](https://roboterminal.app/companies/nabtesco), [SeAH Steel](https://roboterminal.app/companies/seah-steel), [LG Electronics](https://roboterminal.app/companies/lg)

**Tags:** actuators, reducers, supply-chain, humanoids

[Mirle Automation](https://roboterminal.app/companies/mirle-automation)'s subsidiary [Main Drive](https://roboterminal.app/companies/main-drive) plans to go from 100,000 harmonic reducers (the precision gears inside robot joints) a year at the end of 2026 to as many as 10 million a year by the fourth quarter of 2027, according to MoneyDJ (https://www.moneydj.com/kmdj/news/newsviewer.aspx?a=26bac02f-bf9a-4f3f-a3d4-327f6173a532). At roughly 14 harmonic reducers per humanoid, 10 million a year supports about 714,000 humanoids, per a UAnalyze report carried by Cnyes (https://news.cnyes.com/news/id/6620227). The IFR counted nearly 7,000 full-size humanoids sold worldwide in 2025 (https://ifr.org/downloads/press_docs/Market_Presentation_WR_Press_Conference_2026.pdf), a number we took apart in an earlier post (https://roboterminal.app/posts/ifr-2025-robot-installs-vs-humanoids). One supplier's 2027 plan would cover about 100 times the number of full-size humanoids sold in 2025 (arithmetic: 714,000 / 7,000).

A harmonic reducer, also called a strain wave gear, is the compact gearbox that turns a fast-spinning motor into slow, precise, forceful joint movement; its core part is a flexible steel component called the flexspline. [Schaeffler](https://roboterminal.app/companies/schaeffler) put the bottleneck case in writing in August: precision machining of these gears "is time-consuming and capital-intensive and could turn into a major bottleneck in the scaling of humanoid robots in coming years" (https://www.schaeffler.com/en/media/press-releases/press-releases-detail.jsp?id=88210241). The numbers point the other way. China's two volume makers, [Leaderdrive](https://roboterminal.app/companies/leader-drive) and [Laifual](https://roboterminal.app/companies/laifual), are targeting a combined year-end run rate of about 2.16 million units a year (arithmetic), about 54 percent above the 1.4 million robot harmonic reducers that CIC says China shipped in all of 2025 (arithmetic; CIC figure via finet, https://www.finet.com.cn/news/6a432c1e230829983c60be85.html).

That is good news for the humanoid bill of materials and bad news for reducer margins. The bottleneck is being bored out, and the scarce things are moving elsewhere: flexspline steel, forming processes, customer qualification, and signed orders.

## Who is building what, by layer

| Layer | Company | What | Stated capacity or plan | Source |
|---|---|---|---|---|
| Material | [SeAH Steel](https://roboterminal.app/companies/seah-steel) (Korea) | Flexspline steel, previously imported | Supplying SPG since February, now in mass production | Aju Press (https://www.ajupress.com/view/20261006092070729) |
| Reducer | Main Drive / Mirle (Taiwan) | Reducers for a U.S. humanoid program MoneyDJ names as Optimus (unconfirmed) | 100,000/yr end-2026; 800,000/yr Q1 2027; 2M/yr Q3 2027; up to 10M/yr Q4 2027 | MoneyDJ |
| Reducer | Leaderdrive (Suzhou) | #1 in China, #2 globally, about 12% global share | 50,000/month at start of 2026, 70,000 as of a Sep 2 report, goal above 100,000/month by year end | Sina Finance (https://finance.sina.com.cn/wm/2026-09-02/doc-iniqmshw2858902.shtml) |
| Reducer | Laifual (Zhejiang) | 21.4% of China shipments in 2025 | 64,800/month design capacity in July; 80,000/month target by end-2026; 95.1% H1 utilization; backlog above 400,000 units | HKEX interim (https://www1.hkexnews.hk/listedco/listconews/sehk/2026/0828/2026082802825_c.pdf) |
| Reducer | Schaeffler (Germany) | Formed strain wave gearboxes (forming replaces machining) | Validation done; mass manufacturing from 2027 in Germany | Schaeffler |
| Reducer | [Nabtesco](https://roboterminal.app/companies/nabtesco) (production in Germany) | Strain wave gears and actuators for humanoid joints | IATF-certified production in Germany | Nabtesco (https://www.nabtesco.de/en/the-company/presse-detail/compact-precision-drives-for-humanoid-robots-backlash-free-strain-wave-gears-and-actuators-from-nabtesco) |
| Actuator | [LG Electronics](https://roboterminal.app/companies/lg) (Korea) | AXIUM actuators (motor, reducer, drive, PCB) | Fully automated line in Changwon, mass production system by year end; no orders finalized | Edaily (https://en.edaily.co.kr/news/eda202609065029/) |

Main Drive, founded in 2018 by Mirle Group and Hota Industrial, calls itself "Taiwan's first supplier of mass-produced harmonic drive reducers" (https://www.mirle.com.tw/en/news-detail/HumanoidRobots/). Leaderdrive sold 425,000 harmonic reducers in 2025, up 72 percent, and has a three-year exclusive deal with Unitree covering 110,000 units; its share of Chinese humanoids that use harmonic reducers rose from about 70 percent to 80 to 90 percent. Laifual shipped 239,500 units in the first half of 2026, up 112 percent, and says its humanoid customers are moving from product validation to batch purchasing.

## The math: one supplier's plan versus the whole market

Run the IFR count through the 14-reducer assumption. Roughly 7,000 full-size humanoids times 14 harmonic reducers is about 98,000 reducers (arithmetic), just under Main Drive's end-2026 capacity of 100,000. On that rough ruler, the smallest end-2026 capacity figure in the table could have supplied the entire 2025 full-size humanoid market.

The Optimus-linked order points the same way. The U.S. customer ordered 50,000 reducers for delivery before the end of 2026, up from about 10,000 in 2025, per MoneyDJ via Yahoo Taiwan (https://tw.stock.yahoo.com/news/%E7%9B%9F%E7%AB%8B%E6%A9%9F%E5%99%A8%E4%BA%BA%E8%A8%82%E5%96%AE%E6%94%BE%E5%A4%A7-%E5%8A%A0%E5%BF%AB%E6%93%B4%E7%94%A2%E8%85%B3%E6%AD%A5-025800473.html). At 14 per robot, 50,000 covers about 3,600 Optimus-class robots (arithmetic). MoneyDJ describes Mirle as one of the higher-share reducer suppliers in that chain, so the order is a fair sample of what one program needs this year. Main Drive's breakeven is about 300,000 units a year, which at 14 per robot is about 21,400 humanoids a year (arithmetic). The 10 million target is 100 times end-2026 capacity (arithmetic). We covered the same pattern of parts orders outrunning finished robots at https://roboterminal.app/posts/optimus-parts-orders-vs-robots.

The bull forecasts do not close the gap. CMB International, cited by Sina Finance, expects global humanoid sales to go from under 20,000 in 2025 to 2 million in 2030, implying 32 million harmonic reducers, or 16 per humanoid (arithmetic). CIC expects China's robot harmonic reducer shipments to reach 20.7 million in 2030. Main Drive's 2027 plan alone is roughly a third of CMBI's global 2030 figure and about half of CIC's China-only figure (arithmetic: 10 / 32 and 10 / 20.7), before counting Leaderdrive, Laifual, Schaeffler, Nabtesco, or Harmonic Drive Systems, which once held over 80 percent of the global market and is still the technical benchmark.

## What volume does to price

Leaderdrive's average selling price fell from about RMB 1,900 in 2017 to about RMB 1,100 in 2024, a drop of about 42 percent (arithmetic). Its same-spec products sell for 60 to 70 percent of Harmonic Drive Systems' price. Laifual's average price fell from RMB 802 in 2023 to RMB 573 in 2025, about 29 percent (arithmetic), and its unit cost fell from RMB 482 to RMB 351 in a year, about 27 percent (arithmetic).

More capacity chasing the same orders pushes prices down, and humanoid makers collect the difference. Mirle's page puts joint modules at an estimated 50 percent of humanoid hardware cost, and Schaeffler puts actuators at around half of manufacturing cost. A part that heavy in the bill of materials turning into a price-war part is good cost news for any humanoid program.

The margins are less cheerful. Leaderdrive's first-half gross margin slipped about 2.5 points to about 32.26 percent, which it blames on labor costs during rapid expansion. Laifual's gross margin improved to 27.3 percent from 19.8 percent, yet it still lost RMB 71.9 million in the half (adjusted loss RMB 4.1 million) after a net loss of about RMB 170 million in 2025. Main Drive's stated strategy, per MoneyDJ, is niche, highly customized reducers that stay out of price competition in standardized products. A company planning 10 million units a year that still wants to avoid the standard product has a view on where that product's price is headed.

The humanoid slice of this market is still small. China's harmonic reducer market was about RMB 1.3 billion in 2025, of which humanoids were RMB 0.1 billion, about 8 percent (arithmetic). It is expected to reach RMB 1.8 billion in 2026 with humanoids at RMB 0.5 billion, about 28 percent (arithmetic). Fast growth, thin base.

## Where the scarcity goes

When the gear stops being scarce, the inputs to a good gear become scarce. Four show up in the recent announcements.

Start with the steel. SeAH Steel's October 6 announcement matters because Korea had imported the flexspline alloy, including from Japan, and because its claimed advances are the hard parts: alloy design to control deformation during heat treatment and vacuum refining for fatigue life. The club of mills that can pass those tests is probably smaller than the club of shops that can cut gear teeth.

Then the process. Schaeffler says forming instead of machining cuts manufacturing cost by more than 25 percent and material use by more than 75 percent, with key steps taking seconds instead of minutes. It has shipped more than 2 million formed strain wave gearboxes to the automotive sector over ten years. If forming holds humanoid tolerances, the machined-reducer lines going in this year will compete with a process that needs less than a quarter of their material (arithmetic).

Qualification and orders are the last two. Nabtesco leads with IATF-certified production and gears it says deliver 20 percent more torque and 40 percent longer service life than same-size strain wave gears. Baek Seung-tae, an executive vice president who heads LG's HS division, said at IFA on September 5 that "No orders have been finalized with any specific company yet," and Sisajournal-e reported on October 9 that no actuator supply contract with a global company has been confirmed (https://www.sisajournal-e.com/news/articleView.html?idxno=424189). Mirle's own customer is unconfirmed by either party. On the order side, Leaderdrive's backlog is RMB 2.8 billion, about 4.9 times its 2025 revenue of RMB 571 million (arithmetic), with visibility to the third quarter of 2027 and humanoid-related orders above 40 percent. In this market, a signed exclusive like Unitree's 110,000 units looks more valuable than another plant.

## The objection docket

Objection one: these are plans on paper. EYOU Robotics says so directly (https://eyoubot.com/en/industry-news/mirle-main-drive-harmonic-reducer-capacity-expansion), and plans do slip. Leaderdrive's new 1 million unit project moved its ready date from the end of 2026 to the end of 2028, with only 8.39 percent of RMB 1.402 billion in proceeds spent by June 30 (https://www.21jingji.com/article/20260828/herald/1c94f5da8cc7da414d4ffa9419a969f6.html). Fair. But the company's own explanation was low utilization of the lines it already had. Utilization fell from 106.98 percent in 2021 to 42.67 percent in 2024 and recovered only to 67.76 percent in 2025, on implied capacity of about 640,000 units (arithmetic, 433,700 divided by 0.6776), so about a third sat idle (arithmetic). A supplier that delays a plant for that reason is evidence that capacity leads demand.

Objection two: 14 per robot is a guess. Cnyes says so, and Nabtesco notes that planetary gears "are frequently used in humanoid robots" and are usually cheaper to buy. If the real number is lower, overcapacity is worse. If humanoids with more than 40 joints standardize on harmonic drives, it helps. Either way, the plans above are counted in reducers, and the reducer count is what is running ahead of robots.

Objection three: the forecasts could be right. CMBI's 2 million humanoids in 2030 would make 10 million reducers look prudent. Possible. No supplier above has disclosed a confirmed order anywhere near it.

Objection four: tightness is real right now. Laifual ran at 95.1 percent utilization, and small reducers of 52 millimeters and under rose from 5.1 to 10.6 percent of its shipments on humanoid demand. That squeeze is real, and it is exactly what the planned 2.16 million Chinese run rate is being built to erase.

## Three numbers to watch

Main Drive at 800,000 a year in the first quarter of 2027. That step is eight times end-2026 capacity (arithmetic) and passes the 300,000 breakeven. If the Thailand plant reaches its 250,000 to 500,000 range on schedule, the plan is real. If the step slips, treat the 10 million as a planning slide.

Laifual's revenue per unit in the next interim. Its first-half revenue for reducers and other precision parts works out to about RMB 499 a unit (arithmetic, RMB 119.4 million divided by 239,500 units, approximate because the line includes other parts). With 80,000 units a month of capacity and a backlog above 400,000 units, the second half will show whether humanoid demand supports price or only volume.

A signed LG contract. Baek said readiness talks with big tech customers happen in October. A first order would show a large buyer committing to a new joint supplier. No order by year end would point to qualification as the gate.

The gear that was supposed to hold humanoids back is being planned faster than anyone can bolt it into a robot.

## Sources

- [MoneyDJ, Main Drive capacity plan](https://www.moneydj.com/kmdj/news/newsviewer.aspx?a=26bac02f-bf9a-4f3f-a3d4-327f6173a532)
- [Yahoo Taiwan, Mirle humanoid order](https://tw.stock.yahoo.com/news/%E7%9B%9F%E7%AB%8B%E6%A9%9F%E5%99%A8%E4%BA%BA%E8%A8%82%E5%96%AE%E6%94%BE%E5%A4%A7-%E5%8A%A0%E5%BF%AB%E6%93%B4%E7%94%A2%E8%85%B3%E6%AD%A5-025800473.html)
- [Cnyes, UAnalyze 14-reducer math](https://news.cnyes.com/news/id/6620227)
- [EYOU Robotics, Main Drive capacity expansion](https://eyoubot.com/en/industry-news/mirle-main-drive-harmonic-reducer-capacity-expansion)
- [Mirle, Main Drive humanoid reducers](https://www.mirle.com.tw/en/news-detail/HumanoidRobots/)
- [Sina Finance, Leaderdrive capacity](https://finance.sina.com.cn/wm/2026-09-02/doc-iniqmshw2858902.shtml)
- [21st Century Business Herald, Leaderdrive plant delay](https://www.21jingji.com/article/20260828/herald/1c94f5da8cc7da414d4ffa9419a969f6.html)
- [HKEX, Laifual interim results](https://www1.hkexnews.hk/listedco/listconews/sehk/2026/0828/2026082802825_c.pdf)
- [finet, CIC China reducer shipments](https://www.finet.com.cn/news/6a432c1e230829983c60be85.html)
- [Schaeffler, formed strain wave gearboxes](https://www.schaeffler.com/en/media/press-releases/press-releases-detail.jsp?id=88210241)
- [Nabtesco, strain wave gears for humanoids](https://www.nabtesco.de/en/the-company/presse-detail/compact-precision-drives-for-humanoid-robots-backlash-free-strain-wave-gears-and-actuators-from-nabtesco)
- [Aju Press, SeAH Steel flexspline](https://www.ajupress.com/view/20261006092070729)
- [Edaily, LG AXIUM actuators](https://en.edaily.co.kr/news/eda202609065029/)
- [Sisajournal-e, LG actuator contracts](https://www.sisajournal-e.com/news/articleView.html?idxno=424189)
- [IFR, World Robotics 2026 press conference deck](https://ifr.org/downloads/press_docs/Market_Presentation_WR_Press_Conference_2026.pdf)
- [Roboterminal, IFR 2025 robot installs vs humanoids](https://roboterminal.app/posts/ifr-2025-robot-installs-vs-humanoids)
- [Roboterminal, Optimus parts orders vs robots](https://roboterminal.app/posts/optimus-parts-orders-vs-robots)

## Citation

```
"{quote}"
Source: Roboterminal · {url}
```

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Source: Roboterminal · https://roboterminal.app/posts/harmonic-reducer-capacity-vs-humanoids.md