Head to head
FANUC M-20iA vs KUKA KR 20 R3100
A specification duel across payload, reach, precision, and footprint, with a plain read on which arm suits which job.
General-purpose mid arm for handling and welding
Extended reach robot for large envelope handling tasks
Specification duel
Green marks the stronger figure. Unconfirmed specs are shown but not scored.
The verdict
The specs separate them here: the KUKA KR 20 R3100 reaches farther, 3101 mm to 1811 mm. If precision drives the job, the FANUC M-20iA holds the tighter repeatability at ±0.03 mm. They run different controllers, the FANUC M-20iA on the R-30iB Plus and the KUKA KR 20 R3100 on the KR C5, so whichever platform your team already programs and stocks parts for is a real tiebreaker. Mounting options differ: the FANUC M-20iA lists Floor, Ceiling, and Angle, and the KUKA KR 20 R3100 lists Floor, Ceiling, Wall, and Angle. Both are aimed at material handling and machine tending, with the FANUC M-20iA stretching to arc welding and assembly and the KUKA KR 20 R3100 to packaging and dispensing.
Choose this one when
Job fit first, then the controller and cell constraints that decide which arm you can actually install.
Choose the FANUC M-20iA when
- Excellent speed-to-payload ratio
- IP67 wrist tolerates weld spatter and coolant
- Wide selection of mounting orientations
- Mature platform with deep integrator familiarity
Watch for
- Reach is modest for large-part transfer
- Outperformed by lighter arms on pure pick-and-place cycle time
Choose the KUKA KR 20 R3100 when
- Exceptional reach for its payload class
- Good choice for servicing multiple stations
- Solid repeatability at full extension
- Ceiling mount option saves floor space
Watch for
- Long arm needs a rigid mounting structure
- Slower cycle times at full reach compared to shorter arms
Controller ecosystem
Programming habits, spare parts, and pendant familiarity often decide the pick when payloads are close.
- Brand
- FANUC
- Controller
- R-30iB Plus
- Class
- 6-axis industrial
Service, spares, and pendant training for the FANUC M-20iA run through FANUC's R-30iB Plus stack.
- Brand
- KUKA
- Controller
- KR C5
- Class
- 6-axis industrial
Service, spares, and pendant training for the KUKA KR 20 R3100 run through KUKA's KR C5 stack.
These arms run different controllers (R-30iB Plus vs KR C5). If your team already programs one of them, retraining programmers and stocking a second set of spares usually costs more than a small payload or reach advantage on paper.
Mounting, footprint, and mass
How the arm can be oriented in the cell, and how much mass you have to mount.
| Field | FANUC M-20iA | KUKA KR 20 R3100 |
|---|---|---|
| Mounting | Floor, Ceiling, and Angle | Floor, Ceiling, Wall, and Angle |
| Robot mass | 250 kg | 549 kg |
| Protection (IP) | IP67 wrist & J3 arm / IP54 body (IP55 optional) | IP65 |
Heavier arms want stiffer bases and more clearance around the swept volume, and they push freight and rigging costs up on the install. IP ratings only cover the section they name, so a wrist-only rating protects the wrist and nothing else; check the body rating separately before you commit the arm to a washdown or dusty cell.
Application fit
Where each arm is aimed, based on the applications listed on its robot page.
Both pages list material handling and machine tending, with the differences below.
FANUC M-20iA also covers
KUKA KR 20 R3100 also covers
Speed and cycle-time planning
Speed is rarely a single datasheet number across brands. Use payload, reach, and class as the planning frame, then confirm cycle time in a path study.
The FANUC M-20iA is a 6-axis industrial arm rated 20 kg at 1811 mm with ±0.03 mm repeatability. The KUKA KR 20 R3100 is a 6-axis industrial arm rated 20 kg at 3101 mm with ±0.05 mm. Class changes how speed shows up in a cell: collaborative arms slow down near people and can speed up in a guarded mode, while industrial arms run at rated speed inside a fence or scanner field. Which arm cycles faster on your part depends on the path, the payload, and the safeguarding, so confirm the takt with a path study before you quote it.
Common questions
- Which has more payload, the FANUC M-20iA or the KUKA KR 20 R3100?
- The FANUC M-20iA and KUKA KR 20 R3100 match at 20 kg.
- Which reaches farther?
- The KUKA KR 20 R3100 has more reach at 3101 mm versus 1811 mm.
- Which is more precise?
- The FANUC M-20iA holds tighter repeatability at ±0.03 mm.
- Should I choose the FANUC M-20iA or the KUKA KR 20 R3100?
- Match the pick to the job. The FANUC M-20iA is a 6-axis industrial arm at 20 kg and 1811 mm. The KUKA KR 20 R3100 is a 6-axis industrial arm at 20 kg and 3101 mm.
- Do the FANUC M-20iA and KUKA KR 20 R3100 use the same controller?
- No. The FANUC M-20iA uses R-30iB Plus and the KUKA KR 20 R3100 uses KR C5.
- How do the IP ratings compare?
- The FANUC M-20iA is rated IP67 wrist & J3 arm / IP54 body (IP55 optional). The KUKA KR 20 R3100 is rated IP65. Check wrist versus body coverage before washdown or dusty cells.