| Positioning Accuracy | Approximately ±0.005 mm or better under specified test conditions | Check whether the figure refers to positioning accuracy, repeatability, or machining tolerance. These are different measurements and should not be treated as equivalent. | Machine acceptance report, laser interferometer results, test conditions, axis travel length, ambient temperature, and measurement standard. | Critical |
| Repeatability | Consistent bidirectional repeatability suitable for the intended component tolerance | Compare repeatability for linear axes and turret positioning, not only the headline accuracy value. | Bidirectional repeatability test data, ball-bar results, and inspection records from sample parts. | Critical |
| Spindle Speed | Up to 10,000 rpm for high-speed turning and milling applications | Verify whether 10,000 rpm is the maximum speed, the continuous operating speed, or an optional configuration. Higher speed is not automatically better for every material. | Spindle specification sheet, speed-torque curve, continuous-duty rating, balancing grade, and thermal test results. | Critical |
| Spindle Torque | Torque matched to the workpiece material, diameter, and cutting-tool requirements | A high-rpm spindle may have limited torque at low speed. Compare the torque curve rather than rpm alone. | Published torque-power chart, motor rating, drive type, and cutting trial using the target material. | Critical |
| Turning and Milling Capability | Synchronized turning, live tooling, and interpolated milling on the required axes | Confirm whether the machine can complete the required operations in one setup, including drilling, tapping, face milling, slotting, and contour milling. | Axis configuration, live-tool specification, C-axis and Y-axis details, sample programs, and finished-part demonstrations. | Critical |
| Thermal Stability | Stable dimensional performance during extended production cycles | Compare spindle cooling, thermal compensation, machine warm-up procedures, and structural control of heat deformation. | Thermal growth test, warm-up protocol, cooling-system specification, and dimensional inspection after continuous operation. | High |
| Machine Rigidity | Rigid bed, guideways, spindle housing, and turret structure for stable cutting | Evaluate vibration control, heavy-cutting capability, surface finish, and tool-life consistency at the required material-removal rate. | Machine weight, bed construction, guideway design, cutting-force test, surface-finish sample, and vibration data. | High |
| Control System and Data Connectivity | Reliable CNC control with program storage, diagnostics, and common industrial connectivity | Check support for tool management, probing, remote diagnostics, Ethernet data transfer, and production monitoring. | Controller specification, software options, communication protocols, cybersecurity functions, and demonstration of the required workflow. | High |
| Automation Readiness | Compatibility with bar feeders, parts catchers, robots, probing, and automatic tool management | Compare interface availability, loading access, workholding options, chip handling, and integration responsibility. | Automation layout, interface list, I/O documentation, cycle-time study, and integration quotation. | High |
| Work Envelope | Capacity exceeding the largest planned workpiece with adequate tool clearance | Review maximum turning diameter, turning length, bar capacity, chuck size, axis travel, and interference zones. | Detailed machine layout, dimensional drawings, chuck and collet specifications, and a full-scale workholding simulation. | Critical |
| Cycle-Time Capability | Repeatable cycle time validated with the actual part program | Compare rapid traverse, tool-change time, indexing time, acceleration, chip evacuation, and non-cutting time. | Recorded machining video, NC program, cycle-time breakdown, tool list, and sample-part production report. | High |
| Quality Management | Documented production and inspection processes based on recognized quality practices | Assess incoming inspection, process control, final inspection, traceability, calibration, and nonconformance handling. | Quality certificate scope, inspection plan, calibration records, process-control documents, and sample inspection report. | High |
| Factory Acceptance Testing | Formal FAT before shipment using agreed technical criteria | The acceptance test should verify geometry, accuracy, repeatability, spindle performance, safety functions, and sample machining. | Signed FAT protocol, measurement equipment list, test-part drawing, deviation limits, and corrective-action procedure. | Critical |
| After-Sales Support | Defined response times, spare-parts process, remote support, and commissioning assistance | Compare service coverage, technician availability, training, troubleshooting procedures, and escalation channels. | Service-level agreement, spare-parts list, warranty terms, training plan, and support response-time commitments. | Critical |
| Total Cost of Ownership | Transparent five-year cost model rather than purchase price alone | Include machine price, tooling, installation, energy, maintenance, coolant, spare parts, software, training, and downtime risk. | Itemized quotation, energy estimate, maintenance schedule, consumables list, warranty exclusions, and estimated annual operating cost. | Critical |
| Note: Accuracy and spindle-speed figures should be evaluated together with test conditions, machine configuration, workpiece material, tooling, thermal state, and the manufacturer’s formal acceptance criteria. |