Boston Dynamics gives Atlas a 13-DOF four-finger hand
On 1 Oct 2026 Boston Dynamics announced GR3: four-finger Atlas hands, 13 degrees of freedom, sim-to-real training. No pinky. Studio demo, not factory.
Four fingers, motors in the joints, training in simulation. The company says the pinky is not worth the extra cost.
On 1 October 2026 Boston Dynamics announced a new generation of Atlas hands, the humanoid the company sells. In the official video the part is called GR3: four fingers, 13 degrees of freedom, direct actuation at the joints, built to train in simulation and copy that control onto the real robot with reinforcement learning. The company posted on X, put “New Hands for Atlas” on YouTube, and published “Robot Hands for Modern AI and Real Work” on its blog. The Verge wrote it up the same day. The Korea Herald followed on 2 October. The hand is where the humanoid starts handling a tool. The figures below come from the company, except where the press describes the video.
First: what a degree of freedom is
A degree of freedom, or DOF, is each axis the hand can move on its own. Reinforcement learning, or RL, trains a program by trial and error, with a reward when the task works. Sim-to-real means taking what worked in the simulator onto the floor, like a driver who trains in a video game and then gets in the car. The comparison fails when friction, mass, and motor lag are missing from the model.
What changed on the Atlas hands
The previous hand, GR2, had 7 degrees of freedom. The blog says it was designed to grasp a large variety of objects; the new generation is designed to manipulate them. The opposable thumb has 4 axes. Each of the other three fingers has 3. The company’s count: 4 + 3 + 3 + 3 = 13. There is a single actuator type, direct actuation, and, in the company’s wording, “highly transparent” joints. The motors are encapsulated, with no fragile cables crossing the joints, matching the rest of Atlas.
The hand senses its own pose through backdrivable actuators (you can push them back) and has dense tactile pressure sensors on the fingertips and palm. The Verge cites those sensors too. The blog says the hand is similar in size to a large human hand; in the video, the company says it is a little larger than an average human hand and, on average, a bit stronger. No outside lab measured that in this coverage.
Why there is no pinky
The story is internal and comes only from Boston Dynamics. The CTO, spelled Zack in the blog copy and Zach in the video transcript, asked the team to tape the pinky to the ring finger for a day. The team’s conclusion, according to the post, is that the fifth finger did not pay for 3 extra axes, nor the volume, power draw, and extra failure point. The line in the text: “the best part is no part.” The Verge’s summary: the company dropped the pinky to cut cost, size, and failure points.
What the company says the hand can do now
The blog lists what the kinematics are “now capable of”: sliding the thumb tip along and across the other fingers; dexterous pinches between the thumb and any other finger; tripod grasps; and trigger-tool grasps (drills, torque drivers, grinders, nail guns, welding torches). That is a product claim, not evidence from a factory shift.
The Korea Herald describes the video: Atlas seats a bit in a drill, pulls the trigger, and bores into wood; tightens a small nut between the fingers; spins a thin drumstick; handles two golf balls in one hand. The drill is the demo the press actually saw. The rest of the tool list was not checked by a third party here.
The company says it kept force in line with the previous hand, “capable of carrying a 100lb+ loaded minifridge.” That 100 lb+ figure is the payload Boston Dynamics assigns to the new-generation Atlas, and the link points to an older post in which the whole robot lifts a mini fridge. It is not a standalone test of GR3.
Training in the simulator
Human imitation helps, the company writes, but agile dexterous control still needs RL in simulation, as whole-body control already does. The hardware, according to the blog, was built so the virtual dynamics stay close to the real ones. The company reports “initial results showing promising sim2real transfer” on dynamic tasks, trained with domain randomization (the simulator deliberately messes with parameters) and run on hardware using only high-rate actuator proprioception. There is no paper, metric, or trial count: according to the company.
What the announcement does not cover
Torque, hand mass, service life, unit cost, and a mass-production calendar for GR3 were not published. The video does not show wear, dirt, or a part sitting wrong on a line. Read it as a design brief and a studio demo. It does not prove a factory shift.
RUMOR: reading the 100 lb+ mini fridge as a GR3-only strength test. RUMOR as well: the 11:24 Brasília timestamp on the post; the 1 October date is confirmed, the second is not.
Sources
Official
- Boston Dynamics, “Robot Hands for Modern AI and Real Work”
- YouTube, “New Hands for Atlas,” 1 Oct 2026
- @BostonDynamics on X, 1 Oct 2026
- Boston Dynamics, earlier Atlas mini-fridge post (payload context)
Press