ISO 13041-2:2020

Overview

ISO 13041-2:2020 - Test conditions for numerically controlled turning machines and turning centres - Part 2: Geometric tests for machines with a vertical workholding spindle defines how to verify the geometric accuracy of general-purpose, normal‑accuracy NC turning machines and turning centres with vertical spindles. With direct reference to ISO 230‑1 and ISO 230‑7, the standard specifies test types, terminology, axis designations, measuring units (millimetres and angular units), and recommended tolerances for acceptance, comparison and maintenance purposes. It covers only geometric verification (not operational tests such as vibration, speeds/feeds or dynamic behavior).

Key topics and requirements

• Scope and exclusions: Focused exclusively on geometric accuracy verification for vertical‑spindle turning machines; excludes operational or dynamic testing.
• Test suite: A set of geometric tests (designated G1 to G21, plus AR1/AR2) covering spindle/table geometry, linear axes (X, Z), cross‑rail movement, Y‑axis related checks, tool turrets and power driven toolholding spindles. Annexes include rotation‑axis checks and multilingual terms.
• Terminology & axis designation: Standardizes the names and controlled‑axis designations for machines with vertical workholding spindles (figures and tables provided).
• Measurement practice: Calls out referencing ISO 230‑1 and ISO 230‑7 for instrument uncertainty, machine levelling, warm‑up, and measurement methods. Example measuring instruments include DTIs, LVDTs, straightedges and squares (alternative artefacts permitted if uncertainty is adequate).
• Tolerances & units: Tolerances are given as recommendations in millimetres or angular ratios; measurement uncertainty guidance is tied to ISO 230‑1.
• Practical considerations: Guidance on test sequencing, software compensation (to be agreed between user and supplier and reported when used), gravity effects for dual‑rail heads, and instrument selection.

Applications and users

Who benefits:

• Machine tool manufacturers and suppliers - for factory acceptance testing and specification compliance
• Quality, metrology and maintenance engineers - for acceptance, periodic verification and troubleshooting of geometric errors
• Test laboratories and third‑party inspectors - for standardized reporting and comparison of turning centre geometry Practical uses:
• Acceptance testing at delivery and after installation
• Establishing baseline geometric condition for preventive maintenance
• Contractual acceptance criteria in purchase agreements and supplier audits
• Benchmarking machine performance and assessing compensation needs

Related standards

• ISO 230‑1:2012 - Geometric accuracy of machines (test code)
• ISO 230‑7:2015 - Geometric accuracy of axes of rotation
• ISO/TR 230‑11 - Guidance on measuring instruments
• ISO 13041 (other parts) - Additional tests for turning machines
• ISO/TR 16907 - Guidance regarding software compensation

Keywords: ISO 13041-2:2020, geometric tests, NC turning machines, turning centres, vertical workholding spindle, machine tool accuracy, ISO 230‑1, ISO 230‑7, acceptance testing, tolerances.