Korean robot parts makers compared: who builds the hands, actuators, sensors and reducers for Korea's humanoids

Korea's robot-parts makers are strongest in robot hands and force sensors and weakest in precision reducers, the gearboxes that sit in every joint. In MEKAWIRE's verified data, one Korean component maker, Wonik Robotics, has raised growth capital on the scale of a global supplier: KRW 349.99998 billion in convertible preferred shares from Korea Development Bank's Advanced Strategic Industry Fund and an IMM Credit Solution vehicle, filed on Aug 28, 2026. The reducer and motor start-ups are still announcing talks and memoranda.

That gap matters because parts decide humanoid economics. Hyundai Mobis, which agreed in January to supply actuators for the production Atlas, says actuators make up more than 60% of a humanoid's material cost. Whoever supplies joints at volume captures most of the hardware value. This article ranks the Korean contenders by what they have verifiably raised, sold and signed, and asks which layer Korea can realistically own by 2028.

Hands and sensors have the money

Wonik Robotics, the Seongnam maker of the Allegro robot hand, will put KRW 183.9 billion of its KRW 350 billion raise into a robot-hand factory and AX centre in Wanju between 2026 and 2031, according to the filing; payment is scheduled for Nov 20, 2026. MEKAWIRE calculated an implied post-money value of about KRW 1.675 trillion from the share price and count. Investors hold a put option at a 4% IRR if the unit does not list within six years.

AIDIN Robotics, which makes force/torque and tactile sensors, raised KRW 16 billion on Sept 11, of which KRW 13 billion came from HD Hyundai Robotics, according to HD Hyundai's release; the two will co-develop a heavy-duty five-fingered hand for HD Hyundai's humanoid. Tesollo, which makes multi-joint grippers and five-fingered hands, has appointed KB Securities to lead a technology-special listing and expects cumulative sales to pass 1,000 units by the end of 2026, Robot Newspaper reported on Oct 14; the company has not confirmed the figures in a release.

Actuators have a captive buyer, reducers have MOUs

Hyundai Mobis is the only Korean actuator supplier in our data with a named humanoid customer, Boston Dynamics, inside its own group. RS Automation, a servo-drive and encoder maker, is building a platform to link domestic parts makers through a common interface and test bench, Robot Newspaper reported on Oct 14 citing the company. Robotis sells DYNAMIXEL smart actuators and is listed on KOSDAQ.

The reducer layer is thinner. Bonsystems, which makes pinless cycloid reducers and compact actuators, said on Oct 16 that it had held technical talks with Infineon on actuator drivers, according to Edaily; no agreement was disclosed. Nuvinda, a direct-drive and quasi-direct-drive motor start-up founded in 2025 as reported, signed an MOU with Osaka University and Chungnam National University on Oct 12, StartupToday reported.

The benchmark is Japanese

The incumbents show the scale required. Nabtesco estimates it supplies about 60% of the joint reducers in medium and large industrial robots and forecasts precision reduction gear sales of ¥88.2 billion in 2026. Harmonic Drive Systems booked ¥24,128 million of orders in April to June 2026, up 55.7% year on year, a book-to-bill of 1.45 by our calculation, with a backlog of ¥29,457 million. In Europe, Schaeffler has tied actuator supply to humanoid purchases with NEURA Robotics and Humanoid.