A miniature deep groove ball bearing is a type of ball bearing that is designed to be used in small mechanical components and devices. These bearings are typically used in applications where space is limited and where the load on the bearing is relatively low.

Deep groove ball bearings are designed with deep, curved grooves in the outer race that allow the bearing to accommodate both radial and axial loads. The balls in these bearings are typically made of steel and are held in place by the bearing's inner and outer races. The balls, in turn, support the load on the bearing and allow it to rotate smoothly.

Miniature deep groove ball bearings are typically smaller in size than standard deep groove ball bearings and are designed to operate at lower speeds. They are available in a range of sizes, with bore diameters ranging from as small as 1 millimeter to as large as 9 millimeters. These bearings are commonly used in applications such as electric motors, gear boxes, and precision instruments.