MWCNT/HDPE nanocomposite spur gears prepared in concentrations of 0, 0.5, 1, 1.5, 2, and2.5% by weight using centrifugal ball milling dispersion method followed by CNC milling.SEM examination revealed a sound dispersion of the MWCNT in the HDPE matrix until2 wt.%. Nanocomposites exhibited higher decomposition temperature and thermal sta-bility than neat HDPE. Yield strength increased linearly in nanocomposites up to 2 wt.%,and then it saturated. Nanofillers' addition steadily increased the young's modulus up toa weight fraction of 1.5 %, surging rapidly between 1.5 to 2 wt.%. In contrast, its rate ofincrease declined between 2 and 2.5 wt.%. The Taber abrasion test showed a reduction inwear loss of nanocomposites. The nanocomposites' toughness increased between 0 (neatHDPE) and 1.5 wt.% of MWCNT but declined at higher concentrations due to transition fromductile to brittle nature. At a torque of 5 N-m, the wear performance increased consistentlywith the increase in the concentration of nanofillers. At 10 N-m, 2.5 wt.% nanocompos-ite gears displayed a decline due to the increased brittleness. Satisfactory dispersion anddeveloped interphase fervently contributed to the load transfer and mechanical properties.Nanofillers improved the wear resistance, hardness, and lowered plastic deformation. ... mehrThegear damage mechanism changed from thermal bending to tooth cracking and deflection inthe nanocomposite gears. The 2 wt.% MWCNT/HDPE nanocomposites emerged as potentialgearing materials with enhanced hardness, tensile properties, uniform dispersion, thermalstability, wear performance, and reasonable toughness.