In the current paper, hygro-thermo-magnetically induced vibrations of small-scale viscoelastic tubes containing flow with a spin motion under gravity and tangential loads are analyzed by including surface effects. The dynamic equations are derived in the framework of the modified nonlocal elasticity theory (NET) and Rayleigh beam model. The Galerkin method and Laplace transformation are implemented to solve model equations. Vibration frequencies, stability boundaries, and Campbell diagrams of the system are acquired. Impacts of influential parameters such as scale rotary inertia factor, scale parameter, viscoelastic materials, gravity and tangential loads, flow and spin velocities, geometrical properties, and environmental conditions on the stability of the structure are examined. Also, the obtained results are compared for the Rayleigh and Euler-Bernoulli (EB) beam models. The golden results of this work are that by fine-adjusting the scale parameter and magnetic intensity in the system, destructive effects of hygro-thermal loads can be dampened. Besides, the increment of the rotary inertia factor and nanotube thickness induces destabilizing effect on the system. [ABSTRACT FROM AUTHOR]