10 Pcs Deep Groove Ball Bearing Small Bearing Iron Cover Bearing 8mm x 28mm x 9mm, 638ZZ Bearing Steel Z1

Size: 638ZZ (Inner Dia.=8mm, Outer Dia.=28mm, Thickness=9mm) Made from bearing steel, strong durability and resistance to deformity under heavy loads. Hardness 60-62°, high speed, low noise, high precision, Good wear resistance. Closed with metal shields to protect the bearing from dust or any possible contamination. Applicable to: all kinds of mechanical transmission, supporting motors, precision instruments, telecommunications equipment doors and windows pulleys, fitness equipment, toy car models, skateboard roller skating, fishing gear, aircraft model equipment, sewing machinery, household appliances, medical equipment, etc.