Chrome steel miniature bearings for shaft sizes from 1.5mm to 9mm
Dimensions and technical drawings are shown in the product tables below
See Products Variants below for stainless steel and flanged options
Miniature bearings are sometimes referred to as instrument bearings or micro bearings and are used in applications as varied as gyros, anemometers, flow meters, miniature gearboxes, small motors and radio controlled models. Our chrome steel miniature bearings are also available with a flange on the outer ring as shown in Products Variants below.
Chrome steel is the most common material for ball bearings due to its high load capacity and good low noise properties. Chrome steel bearings are also more cost-effective. However, many of the very small, instrument bearings are only made from stainless steel as they are not used in high load applications and the cost difference is negligible due to the small amount of steel used. Our smallest miniature bearings can be found on the stainless steel miniature bearing page (see Products Variants).
Chrome steel bearings, with a steel retainer and a suitable lubricant, can be used at temperatures of 120°C constant or up to 150°C intermittent. Above these temperatures, the load capacity of chrome steel is reduced and the steel undergoes more of a dimensional change than stainless steel.
Chrome steel bearings are not suitable for use in corrosive environments as the steel is not corrosion resistant. Chrome steel miniature bearings are coated with a layer of preservative oil to protect against moisture. We do not recommend using chrome steel bearings without any lubricant (dry) as they are prone to corrosion. This may even occur while in storage or during shipping as a result of condensation forming inside the protective packaging. Protective oil cannot be applied to the outside of a dry bearing as it would find its way inside the bearing making the bearing no longer “dry”.
Most of our chrome steel miniature bearings can be supplied open or with metal shields. The larger sizes may be available with rubber or Teflon contact seals or low friction non-contact rubber seals. Open bearings are supplied with a light oil lubrication. Shielded or sealed bearings are usually supplied with grease lubrication but shielded bearings can be offered with instrument oil for low speed, low friction applications. Thanks to our in-house relubrication facility, these miniature bearings can be offered with customer specified oils, greases or dry lubricants.
The standard cage or retainer for a chrome steel miniature bearing is made from SPCC steel strip. A one-piece crown cage is more common for the smallest and the thinnest bearings due to space constraints. Larger sizes have a two piece ribbon cage. Some sizes are available with a high speed TW nylon crown cage although operating temperatures should be kept under 120°C for this retainer.
Click on INFO in the rows below to display technical drawings of the bearings with load and speed data. Please note that the maximum loads and speeds are used in theoretical life calculations. It is recommended to use bearings at significantly less than the maximum load and speed ratings to ensure reasonable bearing life.