The RU124 cross roller bearing is a reliable, mounting-holed precision bearing with an 80 mm bore, 165 mm outside diameter and 22 mm width. Its integrated inner and outer rings provide a rigid mounting interface, while crossed cylindrical rollers support radial loads, bidirectional axial loads and overturning moments.
With dynamic and static radial load ratings of 33.1 kN and 50.9 kN, the RU124 cross roller bearing is suitable for medium robot joints, CNC rotary tables, servo positioners, semiconductor equipment and medical positioning systems.
LYDL supplies RU124, RU124G and RU124X mounting configurations, together with open, one-side-sealed or double-sealed options. P5, P4 and P2 accuracy, controlled clearance or preload, special grease, OEM marking and inspection reports are available on request.
RU124 Cross Roller Bearing Overview
The RU124 cross roller bearing is an integrated, mounting-holed bearing designed for precision rotary systems requiring a larger center passage, greater supporting rigidity and higher static-load capacity than smaller RU models.
Its principal dimensions are 80 mm bore, 165 mm outside diameter and 22 mm width. Cylindrical rollers are arranged alternately at 90 degrees, enabling a single bearing to support radial loads, axial loads in both directions and overturning moments.
As part of the RU series crossed roller bearings, the RU124 cross roller bearing has mounting holes on both rings. It can be installed directly onto accurately machined supporting components, helping reduce separate bearing housings and clamping flanges.
Key RU124 Advantages
Integrated inner and outer rings
80 mm hollow center passage
33.1 kN dynamic radial load rating
50.9 kN static radial load rating
Direct mounting holes on both rings
Three mounting-hole configurations
Supports inner- or outer-ring rotation
Open, one-side-sealed and double-sealed options
P5, P4 and P2 accuracy available
RU124 Cross Roller Bearing Specifications
Parameter
RU124 Specification
Bearing type
Mounting-holed cross roller bearing
Ring construction
Integrated inner and outer rings
Bore diameter, d
80 mm
Outside diameter, D
165 mm
Width, B
22 mm
Roller pitch circle diameter, dp
124 mm
Minimum chamfer, r min.
1 mm
Greasing-hole diameter, d1
3.1 mm
Reference shoulder diameter, ds max.
114 mm
Reference housing shoulder diameter, Dh min.
134 mm
Inner-ring mounting PCD
97 mm
Outer-ring mounting PCD
148 mm
Basic dynamic radial load rating, C
33.1 kN
Basic static radial load rating, C₀
50.9 kN
Approximate mass
2.6 kg
Standard material
GCr15 / 100Cr6 bearing steel
Available accuracy
P5, P4 and P2
Supported load directions
Radial, bidirectional axial and moment
The stated RU124 cross roller bearing load ratings are radial catalog values. They are not the permissible radial, axial or moment loads of the complete rotary system.
Bearing life and static safety must be evaluated using the actual load combination, overturning-moment arm, speed, operating cycle, preload, lubrication and mounting rigidity.LYDL RU124 integrated cross roller bearing with an 80 mm bore and 165 mm outside diameter.
What Makes the RU124 Cross Roller Bearing Different?
RU124 is the first commonly selected RU size in which mounting-hole direction and thread configuration become important model-selection factors.
Smaller RU42, RU66 and RU85 bearings use a relatively simple mounting-hole arrangement. RU124 adds standard, G and X configurations so equipment designers can select the most practical bolt-access direction.
Larger Hollow Passage
The 80 mm bore provides space for a hollow shaft, reducer output, cables, pneumatic lines or coolant connections. This is useful in robot joints, rotary tables and automation modules requiring internal routing.
Higher Moment-Load Potential
The 124 mm roller pitch diameter and wider ring structure provide a larger supporting geometry than RU85. However, the allowable equipment moment still depends on the combined load, mounting plate stiffness, bolt connection and required bearing life.
Direct Mounting Structure
The integrated rings and mounting holes simplify assembly and can reduce tolerance accumulation. Direct mounting does not remove the need for rigid, flat and accurately aligned supporting surfaces.
View the complete cross roller bearing range if a split-ring structure or different mounting method is required.
RU124 Cross Roller Bearing Mounting-Hole Variants
All three variants use the same 80 × 165 × 22 mm boundary dimensions and the same reference load ratings. The principal difference is the mounting-hole arrangement.
Inner- and outer-ring counterbores face the same direction
RU124G
10 × Ø5.5 through, Ø9.5 counterbore, depth 5.4
10 × Ø5.5 through, Ø9.5 counterbore, depth 5.4
Inner- and outer-ring counterbores face opposite directions
RU124X
10 × M5 threaded through
10 × Ø5.5 through, Ø9.5 counterbore, depth 5.4
Inner ring uses threaded holes
When to Select Each Version
Choose RU124 when both rings can be accessed from the same assembly side.
Choose RU124G when the equipment requires the inner- and outer-ring fasteners to be inserted from opposite sides.
Choose RU124X when bolts must engage directly with threaded holes in the inner ring.
The mounting variant should be confirmed before the housing, output flange and bolt-access spaces are finalized.
Seals, Clearance, Accuracy and Optional Codes
Code
Meaning
Selection Guidance
No seal code
Open bearing
Clean equipment or external sealing
UU
Seals on both sides
Contamination protection and grease retention
U
Seal on one side
Seal on the outer-ring counterbore side
UT
Seal on one side
Seal opposite the outer-ring counterbore side
CC0
Negative clearance or controlled preload
High rigidity and positioning stability
C0
Positive radial clearance
Lower running resistance
C1
Positive clearance greater than C0
Application-specific clearance requirement
P5
Precision grade
General precision automation
P4
High-precision grade
Robot axes and rotary tables
P2
Ultra-high-precision grade
Metrology and demanding positioning systems
R
Outer-ring running accuracy specified
Outer ring is the accuracy-critical rotating ring
B
Inner- and outer-ring running accuracy specified
Either ring may be used as the precision rotating ring
-N
Optional grease nipple
Accessible relubrication point required
When no R or B symbol is specified, the standard model convention normally controls inner-ring rotational accuracy. Confirm the accuracy target with LYDL before ordering.
A detailed purchasing specification may be written as: RU124 / UU / CC0 / P4 / B / G / -N This describes a double-sealed, preloaded, P4-grade RU124G configuration with specified running accuracy for both rings and an optional grease nipple.
Not every application requires all these codes. The approved drawing and purchase order should remain the final authority.
RU124 Cross Roller Bearing Applications
Medium Robot Joints and Positioners
The 80 mm center passage can accommodate a hollow drive shaft, wiring or pneumatic lines. RU124 is suitable for robot shoulder, elbow and wrist structures after the joint loads and moment arm have been verified.
CNC Rotary and Indexing Tables
Its integrated mounting structure and available preload help provide rigidity for rotary tables, indexing units and direct-drive positioning mechanisms.
Semiconductor and Inspection Equipment
RU124 can support rotary wafer-handling modules, optical inspection stages and precision platforms that require stable positioning with an internal service passage.
Medical and Laboratory Systems
The bearing can be considered for imaging mechanisms, treatment-positioning systems and laboratory automation where controlled rotation and a hollow center are required.Typical RU series applications include compact robots, rotary actuators, inspection systems and laboratory automation
Select RU124 when an 80 mm passage, greater rigidity and flexible mounting-hole orientation are required.
Select the RU148 cross roller bearing when higher load ratings and a larger supporting diameter are necessary.
This table supports preliminary size selection only. Use the cross roller bearing selection guide together with an application-specific load and life calculation before final approval.
These models are provided as dimensional and installation references. They should not be described as automatically interchangeable.
Different brand catalogs may specify different dynamic load ratings, static load ratings, tolerances or internal configurations, even when the boundary dimensions and mounting holes are similar.
Before replacement, compare:
Bore, outside diameter and width
Inner- and outer-ring mounting PCDs
Counterbore direction
Inner-ring thread configuration
Seal position
Accuracy grade and controlled rotating ring
Clearance or preload
Starting and running torque
Load ratings and lubricant
Grease-nipple requirement
THK and IKO are trademarks of their respective owners. They are referenced only for model identification and dimensional comparison. LYDL is an independent bearing manufacturer and is not affiliated with or endorsed by these companies.
Engineering Standards Relevant to RU124 Selection
ISO 281 provides general methods for dynamic load ratings and basic rating-life calculations.
ISO 76 covers static load ratings, static equivalent loads and static safety evaluation.
ISO 492 defines general dimensional and geometrical tolerance terminology for radial rolling bearings.
ISO 15243 provides standardized terminology for identifying bearing damage and possible failure causes.
These standards provide general engineering principles. They do not replace the RU124 catalog values, approved LYDL drawing or application-specific calculation.
RU124 Cross Roller Bearing Installation
The RU124 mounting variant must be confirmed before assembly because RU124, RU124G and RU124X require different bolt-access arrangements.
Clean the bearing and both supporting surfaces.
Remove burrs from locating shoulders, counterbores and bolt holes.
Verify the 97 mm inner-ring and 148 mm outer-ring mounting PCDs.
Confirm counterbore direction before positioning RU124 or RU124G.
For RU124X, verify M5 thread engagement and available bolt length.
Place the bearing onto the mounting surface without impact.
Install all ten fasteners loosely before final tightening.
Tighten the fasteners gradually in a diagonal sequence.
Rotate the bearing during staged tightening.
Measure axial and radial runout after assembly.
Confirm starting and running torque before full-load operation.
When a large overturning moment is present, mounting-plate deflection can reduce the benefit of a precision bearing. Supporting-component rigidity and bolt-joint behavior should be reviewed together with bearing accuracy.
A universal bolt torque is not listed because the correct value depends on bolt grade, thread engagement, supporting material, surface treatment and lubrication condition.
RU124 Cross Roller Bearing Inspection and Packaging
LYDL can inspect RU124 according to the selected mounting version, accuracy, preload and documentation requirements.
Available Inspection Items
Bore, outside diameter and width
Mounting-hole diameter and PCD
Counterbore depth and orientation
M5 thread inspection for RU124X
Ring roundness and raceway geometry
Material hardness
Radial clearance or preload
Starting and running torque
Radial and axial runout
Rotation smoothness and noise
Seal, marking and serial-number verification
Inspection reports, material certificates and traceability records can be provided when requested before production.
After inspection, each bearing receives suitable anti-rust protection. Packaging options include sealed or vacuum bags, shock-resistant protection, individual cartons and reinforced export plywood cases.dimensional inspection, rotation testing and protective export packaging at LYDL.
Why Source an RU124 Cross Roller Bearing From LYDL?
LYDL manufactures precision crossed roller bearings in Luoyang, China. Production and quality-control capabilities cover machining, heat treatment, raceway grinding, superfinishing, component sorting, cleaning, assembly, preload verification and final inspection.
Available RU124 configurations include:
RU124, RU124G and RU124X mounting holes
Open, U, UT and UU seal arrangements
P5, P4 and P2 accuracy
Inner-ring, outer-ring or both-ring accuracy control
Controlled clearance or preload
Standard or application-specific grease
Optional grease nipple
OEM marking and traceability documentation
RU124 Cross Roller Bearing FAQ
What is the practical difference between RU124 and RU124G?
Both versions have counterbored holes on the inner and outer rings. On RU124, the inner- and outer-ring counterbores face the same direction. On RU124G, they face opposite directions, allowing bolt access from opposite sides of the assembly.
When should RU124X be selected?
RU124X should be selected when the equipment design requires bolts to engage directly with M5 threaded holes in the inner ring instead of passing through counterbored inner-ring holes.
Does an 80 mm bore mean the complete diameter is available for cables?
No. Clearance should be reserved for cable movement, bend radius, protective sleeves, connectors, shafts and manufacturing tolerances.
Can RU124 support an offset robot payload?
It can carry overturning moment, but the moment created by the payload and its distance from the bearing center must be calculated. Mounting-plate deflection and bolt-joint rigidity must also be considered.
Should I specify R or B accuracy?
Specify R when outer-ring running accuracy is critical. Specify B when the running accuracy of both rings must be controlled. If only the inner ring is the precision rotating ring, the base accuracy specification may be sufficient.
Is the -N grease nipple required for every RU124?
No. Select it only when the assembly requires an accessible relubrication point. Confirm whether the nipple remains accessible after installation.
Can RU124 directly replace CRBF8022A?
It is a dimensional reference candidate. Mounting-hole arrangement, counterbore direction, seals, accuracy, load ratings, clearance, torque and lubrication must be compared before replacement.
Request a Reliable RU124 Cross Roller Bearing Quote
For accurate selection and pricing, provide the quantity, mounting-hole version, seal arrangement, rotating ring, load combination, moment arm, speed, duty cycle, accuracy, clearance or preload, lubricant and inspection requirements. Contact the LYDL engineering team for an RU124 drawing, variant confirmation, load review, production lead time and export quotation.
These sources support dimensional comparison, terminology and engineering principles. They do not replace the approved LYDL drawing, inspection agreement or application-specific engineering review.
