KR 120 R3900-2 K vs X-Arm 6
Side-by-side comparison of KR 120 R3900-2 K (KUKA Robotics) and X-Arm 6 (UFACTORY) — specs, pricing, Robo Index, and verified deployments. Updated daily.
Optimize comparison for buyer
Optimized for Healthcare & Hospitals buyers. Priority specs lifted to the top and marked with a target.
Layer 1: Identity & Trust
Manufacturer Country
- KR 120 R3900-2 KGermany
- X-Arm 6China
Year First Available
- KR 120 R3900-2 K2015
- X-Arm 6—
Verified Deployments
- KR 120 R3900-2 K0 Deployments
- X-Arm 60 Deployments
Layer 2: Operational
Price
- KR 120 R3900-2 K$19,000–$84,900 USD
- X-Arm 6$8,700–$9,500 USD
Availability Status
- KR 120 R3900-2 KACTIVE
- X-Arm 6ACTIVE
Arm Mechanics
Repeatability
- KR 120 R3900-2 K±0.04 mm
- X-Arm 6±0.1 mm
IP Rating (Arm)
- KR 120 R3900-2 KIP65
- X-Arm 6—
Reach
- KR 120 R3900-2 K3,904 mm
- X-Arm 6700 mm
Payload
- KR 120 R3900-2 K146 kg
- X-Arm 63 kg
Degrees of Freedom
- KR 120 R3900-2 K6
- X-Arm 67
Max TCP Speed
- KR 120 R3900-2 K—
- X-Arm 61 m/s
Robot Weight
- KR 120 R3900-2 K42 kg
- X-Arm 611.2 kg
IP Rating (Wrist)
- KR 120 R3900-2 KIP67
- X-Arm 6—
Performance
Duty Cycle
- KR 120 R3900-2 K—
- X-Arm 6continuous 24 7
Controller & Programming
Controller Model
- KR 120 R3900-2 KKR C5, KR C5 micro
- X-Arm 6AC Control Box / DC Control Box
Programming Languages
- KR 120 R3900-2 K—
- X-Arm 6Python, C++
Teach Pendant Type
- KR 120 R3900-2 K—
- X-Arm 6no pendant (browser UI)
Offline Programming
- KR 120 R3900-2 K—
- X-Arm 6UFACTORY Studio
Digital Twin Support
- KR 120 R3900-2 K—
- X-Arm 6Yes
Connectivity
ROS-Industrial Support
- KR 120 R3900-2 K—
- X-Arm 6vendor supported
Predictive Maintenance
- KR 120 R3900-2 K—
- X-Arm 6threshold based
End-Effector
Tool Flange Standard
- KR 120 R3900-2 K—
- X-Arm 6ISO 9409-1-50
Internal Cable Routing
- KR 120 R3900-2 K—
- X-Arm 6through arm and wrist
Commercial
Price (USD)
- KR 120 R3900-2 K$19,000–$84,900 USD
- X-Arm 6$8,700–$9,500 USD
Warranty
- KR 120 R3900-2 K2 yrs
- X-Arm 61 yrs
Service Network
- KR 120 R3900-2 Kglobal
- X-Arm 6regional
Expected Service Life
- KR 120 R3900-2 K—
- X-Arm 63 yrs
| ||
|---|---|---|
| Layer 1: Identity & Trust | ||
| Manufacturer Country (values differ) | Germany | China |
| Year First Available (values differ) | 2015 | — |
| Verified Deployments | 0 Deployments | 0 Deployments |
| Layer 2: Operational | ||
| Price (values differ) | $19,000–$84,900 USD | $8,700–$9,500 USD |
| Availability Status | ACTIVE | ACTIVE |
| Layer 3: Category Specific | ||
| Arm Mechanics | ||
| Repeatability (priority for Healthcare & Hospitals buyers) (values differ) | ±0.04 mm | ±0.1 mm |
| IP Rating (Arm) (priority for Healthcare & Hospitals buyers) (values differ) | IP65 | — |
| Reach (priority for Healthcare & Hospitals buyers) (values differ) | 3,904 mm | 700 mm |
| Payload (values differ) | 146 kg | 3 kg |
| Degrees of Freedom (values differ) | 6 | 7 |
| Max TCP Speed (values differ) | — | 1 m/s |
| Robot Weight (values differ) | 42 kg | 11.2 kg |
| IP Rating (Wrist) (values differ) | IP67 | — |
| Performance | ||
| Duty Cycle (values differ) | — | continuous 24 7 |
| Controller & Programming | ||
| Controller Model (values differ) | KR C5, KR C5 micro | AC Control Box / DC Control Box |
| Programming Languages (values differ) | — | Python, C++ |
| Teach Pendant Type (values differ) | — | no pendant (browser UI) |
| Offline Programming (values differ) | — | UFACTORY Studio |
| Digital Twin Support (values differ) | — | Yes |
| Connectivity | ||
| ROS-Industrial Support (values differ) | — | vendor supported |
| Predictive Maintenance (values differ) | — | threshold based |
| End-Effector | ||
| Tool Flange Standard (values differ) | — | ISO 9409-1-50 |
| Internal Cable Routing (values differ) | — | through arm and wrist |
| Commercial | ||
| Price (USD) (values differ) | $19,000–$84,900 USD | $8,700–$9,500 USD |
| Warranty (values differ) | 2 yrs | 1 yrs |
| Service Network (values differ) | global | regional |
| Expected Service Life (values differ) | — | 3 yrs |
Insufficient data for full comparison
The following fields had no data for any of the selected robots: Battery / Shift Runtime, Path Accuracy, Cycle Time (25/305/25), MTBF, Vibration Damping, Safety Category, Dual Check Safety, Safety I/O Pairs, E-Stop Response, Safe Zone Count, Communication Protocols, IoT / Cloud Platform, Cybersecurity Certs, Tool Changer (ISO), Pneumatic Lines, Electrical Lines, Spare Parts Lead Time
ROI Comparison
Same operating assumptions across every robot — the only difference is price. Set your numbers once to see which pays back fastest.
Annual labor displaced (per robot): $50,000
| Metric | KR 120 R3900-2 K | X-Arm 6 |
|---|---|---|
| Investment | $51,950 | $9,100 |
| Payback period | 12.5 mo | 2.2 mo |
| Net savings (5 yr) | $198,050 | $240,900 |
| ROI (5 yr) | +381% | +2647% |
Estimates labor-cost displacement only — not a full total cost of ownership. Actual ROI depends on integration, maintenance, training, downtime, and task fit. Converted currencies are indicative; USD is the price of record.
Trade-offs at a glance
Frequently asked
Who makes KR 120 R3900-2 K and X-Arm 6?
KR 120 R3900-2 K is made by KUKA Robotics, based in DE. X-Arm 6 is made by UFACTORY, based in CN.
How do KR 120 R3900-2 K and X-Arm 6 compare on the Robo Index?
KR 120 R3900-2 K grades AAA on the Robo Index. X-Arm 6 grades A. The Robo Index is a credibility grade (AAA … C) that blends commercial maturity, verified deployments, company standing, and independent coverage — see methodology for the full breakdown.
How does the reach of KR 120 R3900-2 K compare to X-Arm 6?
KR 120 R3900-2 K has a reach of 3904 mm. X-Arm 6 has a reach of 700 mm.
Are KR 120 R3900-2 K and X-Arm 6 in the same category?
Both robots are classified as Industrial Arm on Robolist. Filters and ranking treat them as direct alternatives.
What is the realistic total cost of ownership for Industrial Arm robots?
Hardware cost is one input. Industrial Arm TCO also includes integration, training, downtime, and end-of-life. Our breakdown: TCO of a 6-Axis Arm Cell: Hardware, EOAT, Integration, Programming.
What should a buyer ask vendors when choosing between KR 120 R3900-2 K and X-Arm 6?
Spec sheets only show part of the story. Useful vendor questions cover support, lifecycle, integration cost, and references. We have a buyer-focused checklist: Industrial Arm Vendor Selection: Capability Matrices and Proof Points.
Going deeper — picking the right robot
TCO of a 6-Axis Arm Cell: Hardware, EOAT, Integration, Programming
7 min readIndustrial Arms
Industrial Arm Vendor Selection: Capability Matrices and Proof Points
9 min readIndustrial Arms
Programming Approaches: Teach Pendant, Offline, AI-Assisted — What Each Costs You
8 min readIndustrial Arms
Build vs buy vs lease: which model fits a first deployment
8 min readChoosing Your First Robot
The hidden specs vendors hope you'll miss
10 min readReading the Spec Sheet
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About this comparison
KR 120 R3900-2 K vs X-Arm 6 compares two robots in the industrial-arm category. All data is sourced from manufacturer spec sheets, verified deployments, and third-party filings; see our methodology for how the Robo Index is calculated.