Spindle Vibration Check — Medium Machines (ISO Class II)
ISO 10816/20816 Class II zone check for 15–75 kW machines or up to 300 kW on rigid foundations.
Most CNC machine-tool spindle motors and machining-center axes fall in Class II. Measure on the bearing housing in three directions; report the worst. A jump of 2× in a month outranks any absolute threshold.
Formula
Note: Condition-monitoring guidance, not a substitute for the machine maker's limits or a qualified vibration analyst on safety-critical equipment.
ISO 10816/20816 Class II zone check for 15–75 kW machines or up to 300 kW on rigid foundations. A free cnc machining: speeds, feeds & tool wear tool — no sign-up, no upload, instant results in your browser.
About Spindle Vibration Check — Medium Machines (ISO Class II)
Spindle Vibration Check — Medium Machines (ISO Class II) computes the governing relationship Class II zone limits: A ≤ 1.12 · B ≤ 2.8 · C ≤ 7.1 mm/s RMS live as you type. Most CNC machine-tool spindle motors and machining-center axes fall in Class II. Measure on the bearing housing in three directions; report the worst. A jump of 2× in a month outranks any absolute threshold. Defaults are pre-filled with realistic values for this exact scenario, and the worked example substitutes your numbers step by step so the math is never a black box.
How to use Spindle Vibration Check — Medium Machines (ISO Class II)
- 1Enter your values — Vibration velocity (RMS) (sensible defaults are pre-filled).
- 2Read the live results: Measured velocity.
- 3Check the "with your numbers" line to see Class II zone limits: A ≤ 1.12 · B ≤ 2.8 · C ≤ 7.1 mm/s RMS substituted step by step.
- 4Adjust inputs until the scenario matches yours, then copy or share the result.
Why use Spindle Vibration Check — Medium Machines (ISO Class II)?
- ✓Instant, free and private — every calculation runs client-side in your browser; nothing is uploaded
- ✓Built on the stated formula Class II zone limits: A ≤ 1.12 · B ≤ 2.8 · C ≤ 7.1 mm/s RMS with authoritative sources cited on the page (ISO 20816-1 (ex 10816) — Mechanical vibration evaluation; ISO 21940-11 — Rotor balancing; ISO 3685 — Tool-life testing with single-point turning tools)
- ✓Most CNC machine-tool spindle motors and machining-center axes fall in Class II.
- ✓SI ⇄ Imperial toggle converts your inputs in place, so you can work in the units your drawings use
Frequently asked questions
What formula does the spindle vibration check — medium machines (iso class ii) use?+
It evaluates Class II zone limits: A ≤ 1.12 · B ≤ 2.8 · C ≤ 7.1 mm/s RMS, exactly as published. Sources: ISO 20816-1 (ex 10816) — Mechanical vibration evaluation; ISO 21940-11 — Rotor balancing; ISO 3685 — Tool-life testing with single-point turning tools. The substituted worked example on the page lets you verify every step against the textbook.
How should I read the result — and how far can I trust it?+
Most CNC machine-tool spindle motors and machining-center axes fall in Class II. Condition-monitoring guidance, not a substitute for the machine maker's limits or a qualified vibration analyst on safety-critical equipment.
When is this calculator the right tool for the job?+
ISO 10816/20816 Class II zone check for 15–75 kW machines or up to 300 kW on rigid foundations. A free cnc machining: speeds, feeds & tool wear tool. Measure on the bearing housing in three directions; report the worst. For neighbouring scenarios, the related tools below cover the same engine with different presets.
Does it support both metric and imperial units?+
Yes — the SI ⇄ Imperial toggle converts the values already in the fields, preserving the physical quantity, so you can flip mid-calculation without re-entering anything.
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