User-supplied ISO input arithmetic
Rigid-Rotor Balance-Quality Arithmetic
Evaluate specific and total permissible residual unbalance from a user-supplied G grade, rotor mass and maximum service speed. The page does not choose a driveshaft grade or allocate tolerance planes.
Unallocated arithmetic result
Dimensionally equivalent forms
The last numerical equality follows because kg·μm equals g·mm. This page performs only that conversion and does not reproduce the normative G-grade table or tolerance-plane allocation.
ISO family boundary
ISO 21940-11:2016 with Amendment 1:2022 establishes procedures and tolerances for rotors with rigid behaviour, including the necessary number of correction planes, allocation to tolerance planes and balancing-process errors. Its current ISO status is published and under systematic review. It explicitly excludes flexible-behaviour rotors.
ISO 21940-12:2016, confirmed in 2025, addresses flexible-behaviour rotors and is not itself intended as a universal acceptance specification. ISO 21940-13:2012 addresses criteria and safeguards for in-situ balancing of medium and large rotors; a generic webpage cannot authorize balancing a driveshaft in a vehicle.
No driveshaft prescription: verify assembly definition, universal/CV joints, phasing, runout, support/bearing conditions, flexible behaviour, balancing speed/procedure, correction locations, measurement uncertainty, product/OEM limits and guards. Do not divide Uper equally between planes unless the applicable allocation procedure justifies it.
