KR 120 R3900-2 K vs STEIN 400
Side-by-side comparison of KR 120 R3900-2 K (KUKA Robotics) and STEIN 400 (STEIN Automation) — specs, pricing, Robo Index, and verified deployments. Updated daily.
Optimize comparison for buyer
Optimized for Warehousing & Logistics buyers. Priority specs lifted to the top and marked with a target.
Layer 1: Identity & Trust
Manufacturer Country
- KR 120 R3900-2 KGermany
- STEIN 400Germany
Year First Available
- KR 120 R3900-2 K2015
- STEIN 400—
Verified Deployments
- KR 120 R3900-2 K0 Deployments
- STEIN 4000 Deployments
Layer 2: Operational
Price
- KR 120 R3900-2 K$19,000–$84,900 USD
- STEIN 400Contact for quote
Availability Status
- KR 120 R3900-2 KACTIVE
- STEIN 400ACTIVE
Arm Mechanics
Payload
- KR 120 R3900-2 K146 kg
- STEIN 40080 kg
Reach
- KR 120 R3900-2 K3,904 mm
- STEIN 400—
Degrees of Freedom
- KR 120 R3900-2 K6
- STEIN 400—
Repeatability
- KR 120 R3900-2 K±0.04 mm
- STEIN 400—
Robot Weight
- KR 120 R3900-2 K42 kg
- STEIN 400—
IP Rating (Arm)
- KR 120 R3900-2 KIP65
- STEIN 400—
IP Rating (Wrist)
- KR 120 R3900-2 KIP67
- STEIN 400—
Controller & Programming
Controller Model
- KR 120 R3900-2 KKR C5, KR C5 micro
- STEIN 400STEIN CONTROL
Commercial
Price (USD)
- KR 120 R3900-2 K$19,000–$84,900 USD
- STEIN 400Contact for quote
Warranty
- KR 120 R3900-2 K2 yrs
- STEIN 400—
Service Network
- KR 120 R3900-2 Kglobal
- STEIN 400—
| | |
|---|---|---|
| Layer 1: Identity & Trust | ||
| Manufacturer Country | Germany | Germany |
| Year First Available (values differ) | 2015 | — |
| Verified Deployments | 0 Deployments | 0 Deployments |
| Layer 2: Operational | ||
| Price (values differ) | $19,000–$84,900 USD | Contact for quote |
| Availability Status | ACTIVE | ACTIVE |
| Layer 3: Category Specific | ||
| Arm Mechanics | ||
| Payload (priority for Warehousing & Logistics buyers) (values differ) | 146 kg | 80 kg |
| Reach (values differ) | 3,904 mm | — |
| Degrees of Freedom (values differ) | 6 | — |
| Repeatability (values differ) | ±0.04 mm | — |
| Robot Weight (values differ) | 42 kg | — |
| IP Rating (Arm) (values differ) | IP65 | — |
| IP Rating (Wrist) (values differ) | IP67 | — |
| Controller & Programming | ||
| Controller Model (values differ) | KR C5, KR C5 micro | STEIN CONTROL |
| Commercial | ||
| Price (USD) (values differ) | $19,000–$84,900 USD | Contact for quote |
| Warranty (values differ) | 2 yrs | — |
| Service Network (values differ) | global | — |
Insufficient data for full comparison
The following fields had no data for any of the selected robots: Battery / Shift Runtime, Path Accuracy, Max TCP Speed, Cycle Time (25/305/25), MTBF, Duty Cycle, Vibration Damping, Safety Category, Dual Check Safety, Safety I/O Pairs, E-Stop Response, Safe Zone Count, Programming Languages, Teach Pendant Type, Offline Programming, Digital Twin Support, Communication Protocols, ROS-Industrial Support, IoT / Cloud Platform, Cybersecurity Certs, Predictive Maintenance, Tool Flange Standard, Tool Changer (ISO), Internal Cable Routing, Pneumatic Lines, Electrical Lines, Spare Parts Lead Time, Expected Service Life
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 | STEIN 400 |
|---|---|---|
| Investment | $51,950 | No price |
| Payback period | 12.5 mo | — |
| Net savings (5 yr) | $198,050 | — |
| ROI (5 yr) | +381% | — |
STEIN 400 has no listed price, so payback can't be computed. Contact the manufacturer for a quote.
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 STEIN 400?
KR 120 R3900-2 K is made by KUKA Robotics, based in DE. STEIN 400 is made by STEIN Automation, based in DE.
How do KR 120 R3900-2 K and STEIN 400 compare on the Robo Index?
KR 120 R3900-2 K grades AAA on the Robo Index. STEIN 400 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.
Are KR 120 R3900-2 K and STEIN 400 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 STEIN 400?
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 STEIN 400 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.