Koyo KOYO6311-2RDC3 Deep Groove Ball Bearing C3 Clearance

Product Description

The KOYO KOYO6311-2RDC3 is a deep groove ball bearing designed for rotating shaft and housing applications across HVAC, pump, motor, and general mechanical equipment. It features a light contact seal on both sides, which reduces friction and running torque compared to full-contact designs while still providing basic protection against contamination ingress. The C3 internal clearance designation indicates a looser-than-standard fit, making this bearing well suited for applications where the shaft and housing experience thermal expansion during operation or where the bearing will be press-fitted into a housing bore. Licensed HVAC techs, millwrights, and mechanical contractors commonly install this type of bearing during blower motor and pump shaft service.

This bearing is appropriate for residential and light commercial applications involving electric motors, centrifugal pumps, fans, and blower assemblies. The 55mm bore, 120mm outer diameter, and 29mm width place it in the 6311 series, a widely used size range in HVAC blower motors and pump drive assemblies. It is installed by technicians servicing rotating equipment where reduced drag and accommodating fits are required by the equipment design.

Key Features

• Light contact seal on both sides reduces running torque while offering basic contamination protection
• C3 internal clearance provides a looser fit suitable for thermal expansion and press-fit installations
• Deep groove design handles radial loads and moderate axial loads in both directions
• 55mm bore accommodates common motor and pump shaft sizes in the 6311 series range
• Low-torque seal construction reduces parasitic energy loss in continuously running equipment

Compatibility

Designed as an OEM-style replacement bearing for electric motors, centrifugal pumps, fans, and blower assemblies requiring a 6311 series deep groove ball bearing with C3 clearance and double-side light contact seals.

Installation Notes

Installation should be performed by a qualified technician using appropriate bearing pullers and press tools to avoid damage to the races or seals. Always de-energize and lock out the equipment before removing the shaft assembly. Apply force only to the appropriate ring during installation to avoid transmitting load through the rolling elements. Consult the equipment manufacturer's service documentation for shaft and housing tolerance requirements before selecting the press or slip fit.

Technical Specifications

• Bearing Series: 6311
• Bore Diameter: 55mm
• Outer Diameter: 120mm
• Width: 29mm
• Seal Type: Light Contact Seal, Double-Sided (2RD)
• Internal Clearance: C3

Standard Information

• Brand: KOYO
• Manufacturer Part Number: KOYO6311-2RDC3