Choosing between industrial robotics cobots and robot-arm equipment can come down to a practical question: do you need a lower-cost unit for parts or restoration, or a used SCARA arm with stated payload and reach specifications? These two 4-axis arms take notably different routes to that decision.
Quick verdict
Pick the 2018 Denso HMS-40704M-W 4 Axis Industrial Robot Arm when the priority is the USD 750.00 listed price and the project is specifically oriented around parts, rebuilding, or working without included controls. Its condition is explicitly listed as for parts or not working.
Choose the Mitsubishi Melfa RH-20SDH8535 SCARA Industrial Robot Arm 4-Axis 20kg Payload when 20 kg payload capacity and 850 mm arm reach are central requirements. It is a used unit, and its external connection wires or umbilical cables were cut during decommissioning. The listed-price gap between the two arms is USD 1,050.00.
At a glance
| Comparison point | Denso HMS-40704M-W | Mitsubishi Melfa RH-20SDH8535 |
|---|---|---|
| Listed price | USD 750.00 | USD 1,800.00 |
| Configuration | 4-axis industrial robot arm | 4-axis SCARA industrial robot arm |
| Condition | For parts or not working | Used |
| Stated working envelope detail | - | 850 mm arm reach |
| Stated payload | - | 20 kg |
| Key project consideration | Controls are not included | External connection wires/umbilical cables were cut |
Where each robot arm fits best
The Denso is the more direct match for a parts-focused budget. The lower listed price is paired with a clear condition designation, so its appeal is in the arm itself rather than a ready-to-run package. The description identifies it as a 2018 Denso unit that was used in an organic food plant, but the lack of controls shapes the decision more than the cosmetic condition.
The Mitsubishi is the more specification-led choice. Its SCARA format, 850 mm reach, and 20 kg payload give an integrator concrete requirements to match against an assembly, material-handling, or packaging plan. Cable termination or replacement is part of the project scope because the external wiring was cut.
Product notes
Denso HMS-40704M-W
The 2018 Denso HMS-40704M-W 4 Axis Industrial Robot Arm is the choice for a project that starts with the robot arm and accepts restoration, parts use, or a controls-related rebuild as part of the work. At USD 750.00, it carries the lower listed price in this comparison. Its 2018 manufacture date and DENSO identification may also help when organizing equipment by model and part number: HMS-4A702E2M 8448 and MPN 410400-3450.
The important limitation is unambiguous: the condition is listed as for parts or not working, and the description says controls are not included. That makes it poorly aligned with a project that needs a complete, immediately controllable robot-arm setup. Its strongest case is a buyer who has a defined use for the arm despite those constraints.
Mitsubishi Melfa RH-20SDH8535 SCARA
The Mitsubishi Melfa RH-20SDH8535 SCARA Industrial Robot Arm 4-Axis 20kg Payload suits work centered on its stated operating envelope: 850 mm reach and 20 kg payload. The RH-20SDH model designation and SCARA configuration make it the clearer selection when those two specifications are the deciding criteria. Its description also positions the arm for high-speed assembly, material handling, and packaging applications that call for a larger envelope.
Its constraint is the decommissioned external cabling. The arm is listed as used, and the external connection wires or umbilical cables were cut, even though the internal wiring mechanisms are described as intact. At USD 1,800.00, this is the higher-listed-price route, best suited to a project that already accommodates external cable work.
Final choice by use case
For parts, restoration, or a lower-entry robot-arm project, choose the Denso HMS-40704M-W. For a SCARA arm where the stated 20 kg payload and 850 mm reach matter more than the cable-work requirement, choose the Mitsubishi Melfa RH-20SDH8535.
