The Chinese Parts Inside Every Humanoid Robot — Including Tesla's Optimus

Ask who's winning the humanoid robot race and you'll get a dozen names — Tesla, Figure, Unitree, Boston Dynamics. But there's a quieter, more important fact underneath all of them: almost every humanoid robot on earth, Western ones included, is built from Chinese parts. The reducers that let a joint move smoothly, the actuators that give it strength, the magnets inside its motors — a startling share of them are made in China, whoever's badge is on the chassis.

Morgan Stanley's widely-cited "Humanoid 100" map of the industry put China at roughly 63% of the entire humanoid supply chain, and about 45% of the "body" — the physical hardware that makes a robot move. The same bank estimated that stripping the Chinese components out of a Tesla Optimus could push its cost from around $46,000 to about $131,000 per unit. That's the story most robot coverage skips: the humanoid revolution is designed in a lot of places, but it is built on a Chinese foundation. Here's who actually makes the parts.

The one number that matters: China owns the body

When Morgan Stanley published its Humanoid 100 in early 2025 — a map of the 100 companies that matter most across the humanoid value chain — the headline wasn't a robot at all. It was geography. Roughly 73% of the companies on the list were Asia-based, and when the analysts weighted the actual "body" of a humanoid — the actuators, gearboxes, motors, screws and sensors — China came out at about 45%, with an overall supply-chain share near 63%. No other country is close on the hardware that makes a robot physically move.

The most quotable illustration is Tesla. Optimus is designed in California and assembled in the United States, but its parts tell a different story. Chinese brokerages that map the Optimus supply chain estimate that a large majority of its component value traces back to Chinese firms, and Morgan Stanley has estimated that rebuilding Optimus without Chinese parts could nearly triple its cost — from about $46,000 to roughly $131,000 — against a target price Elon Musk wants closer to $20,000. Analysts have compared the "Optimus chain" to the iPhone's: engineered in America, physically made in China. It's the same dynamic we traced in who's actually mass-producing humanoids and in why robots are the next global trend after AI.

"You can design a humanoid anywhere. Right now, you can only build one affordably in one place — and that place makes the parts for its competitors too."

Follow the parts: what's actually inside a humanoid

A humanoid robot is, mechanically, a stack of the same few components repeated across 40-odd joints. Walk through them one by one and the Chinese supply chain shows up at almost every layer.

Harmonic reducers — the joints

A harmonic reducer is a compact, ultra-precise gearbox that lets a small motor deliver big, controlled torque — the difference between a jerky joint and a smooth one. Japan's Harmonic Drive Systems is still the global leader, but the world's clear number two is Chinese: Leaderdrive (Green Harmonic), which holds roughly 30–40% of China's harmonic-reducer market according to J.P. Morgan. Founded in 2011 and listed on Shanghai's STAR Market in 2020, Leaderdrive posted 2025 revenue of about 570 million yuan, up 47% year on year, riding humanoid demand. Chinese auto-gear giant Shuanghuan Driveline is scaling reducers too. A single humanoid can use dozens of these gearboxes — 36Kr's teardown of Optimus counted on the order of 28 actuators and 20 small hand motors per robot — so this is high-volume, high-value real estate.

Actuators and motors — the muscles

If reducers are the joints, actuators are the muscles, and here China isn't just a supplier — it's often the sole supplier. Sanhua Intelligent Controls is reported to be the exclusive Tier-1 supplier of Optimus actuator assemblies, with Tesla placing a roughly $685 million order in late 2025 to be filled from a new plant in Mexico. Tuopu Group is reported as the exclusive rotary-actuator supplier for Optimus, with Tesla-related business now a big chunk of its revenue, and it's building frameless and hollow-cup motors — the compact, high-efficiency motors humanoids need. Add Inovance in servo motors and Zhaowei in dexterous-hand modules, and much of the robot's "muscle" is Chinese-made even when the robot isn't.

Rare-earth magnets — the pressure point

Every one of those motors needs a permanent magnet, and the best ones are NdFeB (neodymium) magnets. This is where China's grip becomes geopolitical: according to CSIS, China controls roughly 70% of rare-earth mining, about 90% of processing, and around 93% of magnet manufacturing. In 2025 Beijing tightened the taps — export-licensing rules on medium and heavy rare earths in April, then the strictest controls yet in October — and robot makers felt it immediately. On Tesla's Q1 2025 earnings call, Musk said Optimus production had been affected and that Tesla was working to secure a license, adding: "Hopefully, we'll get a license to use the rare-earth magnets." When a single policy change in Beijing can stall Optimus, you understand how deep the dependency runs. It's the same leverage behind China's push to shape global robot rules.

The one thing China hasn't cracked: roller screws

Here's the honest counterweight to the "China makes everything" story. The hardest single component in a humanoid is the planetary roller screw — the part that converts a motor's spin into a powerful, precise linear push, used in the legs of Tesla Optimus, Figure and most serious humanoids. They demand extreme precision and exotic materials, and it's the one area where Japan and the West still lead the high end and China is visibly catching up rather than dominating. Chinese firms are throwing money at the gap: Beite invested about 1.85 billion yuan in a new base targeting some 2.6 million screw sets a year, Hengli Hydraulic is scaling a lead-screw line, and Wuzhou Xinchun already supplies roller screws for Optimus hip and knee joints. If China closes this gap, the last real bottleneck outside its borders closes with it.

Who makes the parts: the component scoreboard

Here's the honest read on the core mechanical components, sorted by how tight China's grip is on each. The pattern is unmistakable — deep dominance on most of the robot, with one high-precision exception.

Sensors are the other honest caveat. The high-precision six-axis force/torque sensors that let a robot feel how hard it's gripping are still led by Western names like ATI and Schunk; China's Keli Sensing and others are closing in, but this is a second area where the country isn't yet self-sufficient. The "China makes 100% of everything" version of this story is wrong — it's more like 90% of the robot, with two stubborn high-end exceptions.

The "three chains": how China's ecosystem is organized

One useful way to see the Chinese component base, coined by the financial outlet Yicai, is to split it into three overlapping ecosystems — the "Tesla chain," the "Huawei chain," and the "Unitree chain." The framing is more instructive than any single market-share number (and Yicai's own internal percentages are best treated as that outlet's estimates):

That middle one is why our companion piece on Leju's Kuavo, the humanoid running a Huawei-born operating system, matters: the software layer is consolidating in China too, not just the hardware. Between them, these three ecosystems cover almost everything a humanoid needs — which is precisely why the parts flow the way they do.

Why this is the real moat

Strip away the horse-race coverage and this is the most durable fact in the whole category. A Western firm can absolutely design a world-class humanoid — Figure, Boston Dynamics and Tesla all have. What none of them can do today is build one cheaply without reaching into China for the reducers, actuators and magnets. That's why component makers, not just robot brands, are where a lot of the real value sits, and it's a big part of why humanoid prices are so hard to pin down and why the robotics investment wave reaches so far down the supply chain.

It also reframes the timeline question. When people ask when humanoids will actually be ready, part of the answer is a supply-chain answer: mass-market robots arrive when the parts are cheap and abundant, and right now the country making the parts cheap and abundant is China. The West is re-shoring — new screw plants, magnet projects, sensor startups — but that's a years-long build, not a switch to flip. Until it's done, every humanoid on the planet, whatever the badge on its chest, has a little bit of China inside it.

"The humanoid race looks like a contest between American and Chinese robots. Look inside the chassis and it's the same supplier list, over and over — that's the story that actually decides who ships."

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