Vibration Threshold Lookup
Pick your machine class and enter a measured vibration velocity to see its ISO 10816 severity zone — and whether it's time to watch, plan, or act.
Your machine
Zone boundaries for this class (mm/s RMS)
- A / B (good → acceptable)
- 1.4
- B / C (acceptable → warning)
- 2.8
- C / D (warning → alarm)
- 4.5
ISO 10816 zone
Enter a measured velocity to see which ISO 10816 zone your machine is in and what it means.
Want this watched automatically?
Vexron applies these zones per machine class and alerts you as the trend moves toward the C and D lines — no manual routes.
Explore VexronAbout ISO 10816 vibration zones
What is ISO 10816?
ISO 10816 (now largely superseded by ISO 20816, which keeps the same zone concept) is the standard for evaluating machine vibration by measuring overall vibration velocity on non-rotating parts such as bearing housings. It sorts a reading into four zones — A, B, C and D — that run from a newly commissioned healthy machine to vibration severe enough to cause damage.
What do zones A, B, C and D mean?
Zone A is the vibration of a new machine in good condition. Zone B is acceptable for unrestricted long-term operation. Zone C is unsatisfactory for long-term operation — the machine can run for a limited period, but plan an intervention (your warning line). Zone D is vibration severe enough to cause damage (your alarm line).
Why do the limits change with machine size and mounting?
A small pump and a large motor do not vibrate the same way at the same health, so ISO 10816-3 groups machines by power (roughly 15–300 kW vs above 300 kW) and by support type (rigid vs flexible). Larger machines and more flexible mountings tolerate higher velocities before crossing into the warning and alarm zones. A single site-wide threshold is almost always wrong.
Is this tool a substitute for the ISO standard?
No. It uses the standard's published reference limits as a guide to help you interpret a reading quickly. For formal assessment, refer to ISO 10816-3 / ISO 20816 directly, and always set alarms against the individual machine's own baseline and trend as well as the generic zones.
Should I alarm on the absolute value or the trend?
Both. The zone boundaries give an absolute reference, but a reading climbing steadily through Zone B often matters more than one that has sat flat in Zone C for years. Continuous monitoring makes the trend visible; a periodic handheld reading only gives you snapshots.
Read the full guide
Our plain-language explainer covers the zones, why the limits shift with machine class, and how to turn them into alerts.