Topic · Updated 28 August 2026
Who supplies humanoid actuators and reducers?
The joint is the most expensive thing in the robot and the hardest to second-source. Who makes the motor, the reducer and the screw, where those lines physically sit, and which parts have no domestic producer at all.
40–60%
Actuation share of humanoid BOM cost
Third-party
0
US volume producers of strain-wave reducers
Third-party
>50%
Share of Humanoid's wheeled-platform actuator demand Schaeffler supplies through 2031
Company-claimed
None
Harmonic reducers in Unitree's disclosed actuator architecture
Filing-grade
The current answer
- 01Actuation is 40 to 60 percent of humanoid bill-of-materials cost, so the supplier question at this layer determines the economics of the whole machine. Core Matter estimate, August 2026.
- 02No United States supplier makes strain-wave reducers at volume. That is the single binding constraint on domestic humanoid content, and it has no near-term fix, because the component is a precision-manufacturing problem rather than a capacity problem.
- 03Most off-the-shelf robotics actuators are made by mainland Chinese manufacturers, Daimon and CubeMars among them. The incumbent precision reducer makers are Japanese: Harmonic Drive Systems, Nabtesco and Shimpo.
- 04Under the FCC domestic-content rule there is no allied tier. Harmonic Drive Systems, Nabtesco and Shimpo fail the test identically to Leaderdrive, because the rule asks where a part was manufactured rather than where the company is from.
- 05Domestic production does exist at the motor and screw layers. Frameless and precision motors: maxon (manufacturing in Taunton, Massachusetts since 2019), Kollmorgen, Celera Motion, ThinGap. Roller screws: Nook Industries, Creative Motion Control. Schaeffler runs precision bearing lines in Cheraw, South Carolina, and Danbury and Winsted, Connecticut.
- 06Unitree's disclosed actuator architecture does not use harmonic reducers, which is the most consequential single disclosure from its August 2026 IPO roadshow for anyone modelling the reducer market. Filing-grade.
- 07Schaeffler's binding five-year agreement with the UK maker Humanoid covers more than 50 percent of that company's wheeled-platform actuator demand through 2031, at seven-digit actuator unit volumes against a four-digit fleet by 2032. Company-claimed, May 2026.
The actuator stack, by layer and by where it is made
The FCC test asks where a part was manufactured, not where the company is headquartered. The question for any supplier is which SKUs come off which line.
| Layer | Incumbent suppliers | US-manufactured option | Status |
|---|---|---|---|
| Strain-wave (harmonic) reducer | Harmonic Drive Systems, Nabtesco, Shimpo (JP); Leaderdrive (CN) | None at volume | Binding constraint |
| Frameless and precision motors | Daimon, CubeMars (CN) | maxon (Taunton, MA), Kollmorgen, Celera Motion, ThinGap | Domestic option exists |
| Roller and ball screws | Mixed | Nook Industries, Creative Motion Control | Domestic option exists |
| Precision bearings | Schaeffler, mixed | Schaeffler (Cheraw SC; Danbury and Winsted CT) | Domestic option exists |
maxon is Swiss and Schaeffler is German. Both manufacture in the United States, which is what the rule measures. Sourcing from Japan or Taiwan does not help, because the rule splits domestic from everything else with no allied tier.
The research behind this answer
Every Core Matter piece that contributed to the figures above, newest first, with what each one added.
Atlas
28 August 2026
The actuator atlas: interactive joint and actuator maps
Interactive exhibits: the route each joint takes on the Unitree G1 and Tesla Optimus, and an exploded view of the integrated module on both reducer routes.
Report
12 August 2026
Unitree's IPO roadshow, translated: what Wang Xingxing told 360 investors
Disclosed an actuator architecture with no harmonic reducers, from the shipment leader.
Newsletter
30 July 2026
The FCC did not ban Chinese robots. It set a bill-of-materials test
Named the strain-wave reducer as the binding constraint, and mapped which actuator layers have a US-manufactured option today.
Report
17 June 2026
17,000 humanoids shipped last year. Almost none went to work.
Vertical integration into motors, reducers and encoders as an iteration-speed advantage measured in days rather than months.
Newsletter
6 June 2026
NVIDIA's open humanoid runs on Chinese components
Which actuator parts a US open reference design actually specifies, and where they are made.
Newsletter
28 May 2026
Humanoid's two-German-supplier bet against the Tesla playbook
The Schaeffler and Bosch agreements, and what a binding multi-year actuator supply deal looks like in volume terms.
What this answer cannot cover yet
- 01A full actuator primer covering the Japan, China and United States three-way market, with factory-quoted pricing, is in progress and not yet published. Pricing detail is held until it ships.
- 02Whether the actuation share of BOM is rising or falling over time is a live question. The published range is a point estimate for 2026.
Related topics
How to read the figures
Every figure on this page is labelled by provenance. Filing-grade means it comes from a regulatory filing. Company-claimed means the company stated it. Third-party means a tracker, retail listing, teardown, or Core Matter estimate. This page is updated as new research lands rather than republished, and the date at the top is the last time a figure on it moved.
Research access
This answer moves when new work lands
The research that updates this page is published as it is finished, built from company filings, datasheets and direct factory pricing.