ISO 10791-2:2023

Overview

ISO 10791-2:2023 - Test conditions for machining centres - Part 2: Geometric tests for machines with vertical spindle (vertical Z‑axis) defines standardized geometric tests, measurement conditions and tolerances for vertical‑spindle machining centres and compatible numerically controlled (NC/CNC) machines. The document focuses exclusively on geometric accuracy (no-load or quasi‑static conditions) for machines with three numerically controlled linear axes (X ≤ 5 000 mm, Y ≤ 2 000 mm, Z ≤ 2 000 mm) and addresses supplementary rotary and tilting movements.

Key topics and technical requirements

• Scope and applicability: Tests for general‑purpose and normal‑accuracy machining centres; partial applicability to other NC machines when configurations match test requirements.
• Geometric tests grouped in Clause 5: Straightness, angular errors, squareness between axes and spindle related checks (tests referenced to ISO 230 series).
• Table configurations (Clauses 6–9): Procedures for four table types:
  • Horizontal non‑rotating tables (Clause 6)
  • Tables rotating around a vertical C’‑axis (Clause 7)
  • Tables rotating and tilting about a horizontal A’‑axis (Clause 8)
  • Tables rotating and tilting about a horizontal B’‑axis (Clause 9)
• Annexes A–C (informative): Error‑motion tests for spindle rotation, rotary tables and tilting cradles.
• Measurement practice: Reference to ISO 230‑1 and ISO 230‑7 for installation, warming up, measurement uncertainty and methods; use of millimetres for linear errors and angular ratios/microradians for angular errors. Consideration of relative (differential) measurements where single‑instrument measurement is not possible.
• Outputs defined: Test sequences, measurement instruments, diagrams, software compensation guidance and tolerances for acceptance/maintenance.

Practical applications

• Acceptance testing and factory acceptance: Verify delivered CNC machining centres meet declared geometric accuracy.
• Commissioning and installation: Baseline geometric checks after site installation and alignment.
• Preventive maintenance and troubleshooting: Periodic verification to track drift, plan repairs, and validate software compensation.
• Comparative testing and procurement: Objective basis to compare machines or suppliers using standardized test methods and tolerances.

Who should use this standard

• Machine tool manufacturers and OEMs for design verification and factory testing.
• Quality and metrology labs performing acceptance or periodic geometric testing.
• Production engineers and maintenance teams responsible for machine capability and traceability.
• Buyers and procurement teams needing objective performance criteria for vertical‑spindle machining centres.

Related standards

• ISO 230‑1: Geometric accuracy of machine tools (test code)
• ISO 230‑7: Geometric accuracy of axes of rotation
• ISO 10791‑6: Kinematic tests for machining centres

Keywords: ISO 10791-2:2023, machining centres, geometric tests, vertical spindle, CNC, tolerances, ISO 230, rotary tables, tilting tables, machine tool accuracy.