Test Code Standard
ISO 230 Standards Reference
Choose the correct ISO 230 test family before reading a detailed acceptance guide or comparing machine-tool accuracy reports.
Use this ISO 230 series selector to choose the correct test family before reading a detailed acceptance guide.
ISO 230-2 = positioning accuracy and repeatability; ISO 230-4 = circular interpolation behavior; ISO 230-7 = rotary-axis geometric accuracy.
ISO Acceptance Decision Path
Follow this path from ISO overview to geometric-test method, axis reports, series selection, and GB/T 17421 mapping.
Why ISO 230 Matters
When buying, relocating, or accepting a CNC machine, ISO 230 references help separate geometric checks, positioning checks, circular interpolation checks, thermal behavior, and rotary-axis checks. Use the signed acceptance protocol to decide which parts apply and which measured limits must be met.
Acceptance standard
ISO 230 Machine Tool Standards Selector
ISO 230 series selector for geometry, positioning, thermal, circular, diagonal, and rotary-axis acceptance checks.
| Standard | Focus | Primary evidence | Acceptance use |
|---|---|---|---|
| ISO 230-1 | Geometric accuracy | Straightness, flatness, squareness, parallelism checks | Use for no-load geometry acceptance before process trials. |
| ISO 230-2 | Positioning accuracy | Laser/interferometer positioning and repeatability report | Use when axis accuracy and repeatability limits are contracted. |
| ISO 230-3 | Thermal effects | Thermal drift measurements under defined conditions | Use when warm-up, environment, or spindle heat affects acceptance. |
| ISO 230-4 | Circular tests | Ballbar or circular interpolation evidence | Use to check servo mismatch, reversal spikes, and contouring behavior. |
| ISO 230-6 | Diagonal displacement | Body diagonal or volumetric displacement check | Use for quick volumetric accuracy screening. |
| ISO 230-7 | Rotary-axis geometry | Rotary table or A/B/C axis geometric evidence | Use for 4-axis and 5-axis machine acceptance. |
ISO 230 Series Breakdown
| Standard | Title / Focus | Key Tests & Description | Primary Tool |
|---|---|---|---|
| ISO 230-1 | Geometric Accuracy | Straightness, Flatness, Squareness, and Parallelism of axes. Done under "No Load". | Granite Square, Level |
| ISO 230-2 | Positioning Accuracy | Determines positioning accuracy, repeatability, and reversal behavior on numerically controlled axes. | Laser Interferometer |
| ISO 230-3 | Thermal Effects | Measures axis drift due to environmental temperature changes and spindle heat generation. | Displacement Sensors |
| ISO 230-4 | Circular Tests | Dynamic contouring accuracy. Identifies servo mismatch, reversal spikes, and stick-slip. | Telescoping Ballbar |
| ISO 230-5 | Noise Emission | Sound pressure levels during operation. | Decibel Meter |
| ISO 230-6 | Diagonal Displacement | Volumetric accuracy check by moving along body diagonals (Body Diagonal Test). | Laser Tracer |
| ISO 230-7 | Rotational Axes | Geometric accuracy of rotary tables (A, B, C axes). Center of rotation error. | Test Arbor / Laser |
ISO 230 Acceptance Overview
Map standards to machine sign-off evidence.
Deep Dive: ISO 230-2
Understanding A, R, and B values.
ISO 230-3 Thermal Effects
Coming Soon: How to test thermal drift.
Related Calculators
Use these calculators when machine-tool accuracy standards need to feed back into procurement, maintenance, or lifecycle cost decisions.
Frequently Asked Questions
What is ISO 230 and what does it cover?
ISO 230 is a family of standards for testing geometric accuracy and positioning of CNC machine tools. ISO 230-2 covers linear axis positioning accuracy, ISO 230-4 covers circular tests, and ISO 230-6 covers diagonal displacement.
What environment is required for ISO 230 testing?
ISO 230-1 specifies 20°C ± 2°C ambient temperature with maximum gradient of 1°C/hour. Temperature must stabilize for minimum 24 hours. Humidity should be below 75%. Vibration must be below threshold values.
What is the difference between accuracy and repeatability in ISO 230-2?
Accuracy is how close the machine positions to the commanded position (systematic error). Repeatability is how consistently it returns to the same position (random error). World-class: accuracy ±0.005mm, repeatability ±0.002mm.
How often should CNC machine accuracy be tested?
Best practice: full ISO 230-2 test annually, laser check semi-annually, and ballbar (ISO 230-4) quarterly. High-precision shops (aerospace, medical) may test monthly. Always re-test after a crash or relocation.
What is the Chinese equivalent of ISO 230?
GB/T 17421 is the Chinese national framework commonly mapped to ISO 230 topics. GB/T 17421.2 corresponds to ISO 230-2 positioning accuracy; always compare the exact edition, clause references, supplier report template, and contract acceptance language before treating two reports as equivalent.