ISO 20816 vs ISO 10816: What Changed in the Standard
ISO 20816 vs ISO 10816: What Changed in the Vibration Standard?
If you have searched for machine vibration limits recently, you have probably run into two standard numbers that look almost identical: ISO 10816 and ISO 20816. The short answer to which one matters: ISO 20816 is the newer, unified standard that is gradually replacing ISO 10816. It merges two older series — ISO 10816 (vibration measured on the casing and bearing housings) and ISO 7919 (vibration measured on the rotating shaft) — into a single framework.
The reassuring part for anyone doing day-to-day monitoring: for everyday casing measurements, the acceptable mm/s limits did not change. A reading you judged against ISO 10816-3 lands in the same zone under ISO 20816-3. This guide explains exactly what changed, what stayed the same, and which standard you should reference — and if you just want to start taking readings, the Vibration Detector Sensor app gives you live RMS velocity in mm/s for either standard.
Measuring casing vibration? Both standards use the same number
Read your machine’s RMS velocity in mm/s and judge it against either ISO 10816-3 or ISO 20816-3 — the zone limits are identical. Your iPhone’s accelerometer is all you need to start.
What is ISO 10816?
ISO 10816 is the long-standing standard for evaluating machine vibration by measuring it on the non-rotating parts — bearing housings, casings and machine feet — using seismic sensors such as accelerometers. It defines the familiar severity zones A, B, C and D and the mm/s velocity boundaries between them. Its most-used part, ISO 10816-3, covers general industrial machines above 15 kW running between 120 and 15,000 RPM, and has been the backbone of condition-monitoring programs for over a decade. You can capture the exact readings these zones require with the phone-based vibration meter.
Running in parallel for years was a second standard, ISO 7919, which dealt with a completely different measurement: the vibration of the rotating shaft itself, captured by non-contact proximity probes (eddy-current sensors). Shaft vibration is the more telling parameter for large turbines and generators, where the rotor’s motion inside its bearing clearances matters more than the housing’s.
What is ISO 20816?
ISO 20816 is the modern successor that unifies those two philosophies. Recognising that thorough monitoring of critical machinery often needs both housing vibration (for structural assessment) and shaft vibration (for rotor-dynamic assessment), ISO consolidated ISO 10816 and ISO 7919 into a single, coherent series under the title “Mechanical vibration — Measurement and evaluation of machine vibration.”
The rollout has been gradual and part-by-part. ISO 20816-1 (general guidelines) was published in 2016, superseding ISO 10816-1. ISO 20816-3 (general industrial machines) arrived in 2022, replacing both ISO 10816-3 and ISO 7919-3. Other parts — turbines, hydro sets, wind turbines and more — continue to migrate over time, which is why both numbering systems are still in active use. Whichever applies to your equipment, the sensor app handles the casing-side measurement.
ISO 20816 vs ISO 10816: the key differences
Here is a side-by-side of what actually changed between the two, focused on the most-used industrial part (Part 3):
| Aspect | ISO 10816 | ISO 20816 |
|---|---|---|
| What it measures | Casing / bearing-housing vibration only | Unified: casing and rotating-shaft vibration |
| Standards it replaces | ISO 2372 | ISO 10816 + ISO 7919 |
| Part 1 published | 1995 | 2016 |
| Part 3 published | 2009 | 2022 |
| Speed range (Part 3) | 120–15,000 RPM | 120–30,000 RPM |
| Machine groups (Part 3) | Groups 1–4 (3 & 4 were pump categories) | Groups 1 & 2 only; pumps treated as standard |
| Equipment scope | Traditional rotating machines | Adds conveyors, variable-speed couplings, etc. |
| Zone A/B/C/D limits (casing) | Baseline values | Essentially unchanged |
The headline change: ISO 20816 did not rewrite the limits — it widened the scope. It folded shaft-vibration evaluation into the same document, extended the speed range, and tidied up the machine groupings. The mm/s thresholds you already know are intact.
Did the vibration limits (mm/s) actually change?
For casing and bearing-housing vibration — the kind you measure with an accelerometer or a phone — the zone boundaries carried over almost identically. The Group 1 and Group 2 values below are the same whether you cite the older or newer standard:
| Group & support | A/B (mm/s) | B/C (mm/s) | C/D (mm/s) |
|---|---|---|---|
| Group 2 (15–300 kW) — Rigid | 1.4 | 2.8 | 4.5 |
| Group 2 (15–300 kW) — Flexible | 2.3 | 4.5 | 7.1 |
| Group 1 (>300 kW) — Rigid | 2.3 | 4.5 | 7.1 |
| Group 1 (>300 kW) — Flexible | 3.5 | 7.1 | 11.0 |
The most visible structural change is that ISO 10816-3 used to carry separate groups for pumps (the old Groups 3 and 4); ISO 20816-3 dropped those and now evaluates pumps as ordinary rotating equipment by power, with rotodynamic pumps still able to reference the dedicated pump standard. You can confirm where your own machine falls by taking a live reading with the accelerometer tool and matching it to the table above.
Which standard should you use?
For new specifications, acceptance tests and fresh monitoring programs, reference ISO 20816 — it is the current standard and will be the long-term reference. For existing contracts, legacy monitoring systems and historical trend data, ISO 10816 remains perfectly valid, and many plants will keep citing it for years. Because the casing limits match, you are not creating a conflict by running both during the transition.
✓ Practical takeaway: If a vendor quotes a limit “per ISO 10816-3” and your new policy says ISO 20816-3, you do not need to re-baseline. The same mm/s reading produces the same A/B/C/D verdict. Just keep your measurement point, direction and load consistent.
What this means if you measure with a phone
A smartphone accelerometer measures casing and bearing-housing vibration — precisely the side of the standard that both ISO 10816 and ISO 20816 cover with the same mm/s zones. That makes a phone an ideal screening tool for the most common monitoring task: tracking overall RMS velocity on motors, pumps, fans and gearboxes and flagging anything drifting toward Zone C.
What a phone cannot do is the shaft-vibration side that ISO 20816 newly absorbed from ISO 7919 — that requires permanently installed proximity probes inside the machine and is reserved for large turbomachinery. For everything else, the Vibration Detector Sensor app covers the housing-vibration workflow end to end: live RMS and peak in mm/s, a frequency spectrum to find the cause, session logging and CSV export for your records. You can review the full feature set on the app’s home page.
One number, either standard — measure it free
Get live RMS & peak vibration in mm/s, a dominant-frequency spectrum, and exportable session logs — everything you need to apply ISO 10816-3 or ISO 20816-3 casing limits from your iPhone.
► Get Vibration Detector Sensor on the App Store | Explore the app →
Note: A smartphone accelerometer is well suited to screening and trending of casing vibration, but it is not a substitute for a certified, calibrated analyser — or for shaft proximity probes — when compliance-grade or rotor-dynamic measurements are required.
Frequently Asked Questions
Is ISO 10816 still valid, or do I have to switch to ISO 20816?
ISO 10816 is still valid and widely used. ISO 20816 is the current standard for new work, but the transition is gradual and both are accepted during the changeover. Because the casing-vibration limits are essentially the same, existing programs that cite ISO 10816 do not need to be reworked.
What replaced ISO 10816?
ISO 20816 replaced ISO 10816, combining it with the shaft-vibration standard ISO 7919 into one unified series. ISO 20816-1 superseded ISO 10816-1 in 2016, and ISO 20816-3 replaced ISO 10816-3 (and ISO 7919-3) in 2022, with other parts migrating over time.
Did ISO 20816 change the vibration limits?
For casing and bearing-housing measurements, the A/B/C/D zone boundaries in mm/s carried over essentially unchanged. ISO 20816 mainly widened the scope — adding shaft-vibration evaluation, extending the speed range to 30,000 RPM, and simplifying machine groupings — rather than altering the numbers.
What is the difference between ISO 7919 and ISO 10816?
ISO 10816 covers vibration measured on non-rotating parts (bearing housings, casings) with accelerometers, while ISO 7919 covered vibration measured directly on the rotating shaft using non-contact proximity probes. ISO 20816 unifies both into a single standard so machines can be evaluated on housing and shaft together.
When was ISO 20816 published?
ISO 20816-1, the general-guidelines part, was published in 2016. The widely used industrial part, ISO 20816-3, was published in 2022. The series is being released part by part, which is why some equipment types still reference the older ISO 10816 numbering.
Does ISO 20816 apply to machines under 15 kW?
Like ISO 10816-3 before it, ISO 20816-3 applies to industrial machines above 15 kW. Smaller machines fall outside its formal scope, though the older Class I severity bands (good below about 0.71 mm/s) are commonly used as practical guidance for small motors.
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