Stieber is a specialist manufacturer of freewheels, overrunning clutches, one-way clutches and backstops for industrial drive systems. Founded in Munich in 1937, the company focuses on engineered power-transmission solutions and today operates as part of the Regal Rexnord Group. Stieber products are designed around controlled torque transmission in one direction and automatic disengagement or freewheeling in the opposite operating condition.
For maintenance, machine building and industrial drive applications, correct Stieber selection depends not only on dimensions but also on the freewheel function, torque, rotational speed, direction of rotation, bearing arrangement, lubrication and mounting method.
What Is a Stieber Freewheel?
A freewheel is a directional coupling that engages and disengages automatically according to the relative direction of rotation between the driving and driven components.
Stieber identifies three fundamental operating functions:
Overrunning clutch – automatically disengages when the driven component rotates faster than the driving component.
Indexing clutch – converts reciprocating movement into intermittent rotational movement.
Backstop – permits rotation in one direction while preventing reverse rotation.
This distinction is fundamental when selecting a Stieber unit. Two freewheels with apparently similar dimensions may be designed for different operating conditions and should not be considered interchangeable without checking the complete technical specification.
Stieber Product Range
The current Stieber portfolio is divided into several principal product groups: Built-In Freewheels, Centrifugally Lift-Off Sprag Freewheels, Combined Bearing Freewheels, Self-Contained Freewheels and Custom Products.
Stieber Built-In Freewheels
Built-in freewheels are intended for integration into the surrounding machine construction.
The range includes:
AA, AE, AS, ASNU, DC, DC Races, NF and NFR.
For example, Stieber AA is a roller-type freewheel without integrated bearing support. The surrounding installation must therefore provide the bearings as well as lubrication and sealing.
Stieber NFR, by comparison, is a bearing-supported roller-type freewheel without sealing. Stieber specifies oil as the standard lubricant, while the installation must provide appropriate sealing.
Stieber CSK Freewheels
The CSK family is particularly important when searching for compact bearing/freewheel solutions.
Stieber lists:
CSK, CSK..2RS, CSK..P, CSK..P2RS and CSK..PP.
The manufacturer describes CSK as a bearing/freewheel with dimensions corresponding to ball-bearing series 62. The P and PP variants introduce keyways in the inner race or in both races depending on the version, while 2RS identifies sealed variants.
Because the complete suffix changes the construction, always identify the full Stieber designation rather than searching only for “CSK”.
Stieber GFR and GFRN Freewheels
The GFR and GFRN families provide roller-type freewheel modules with several configurations for integration into industrial drives.
Available versions include GFR, GFRN, GFR..F1F2, GFR..F2F3, GFR..F2F7, GFRF3F4 and GFRN..F5F6.
Selected GFR/GFRN combinations are self-contained, sealed and bearing-supported using two 160-series bearings. Stieber states that configurations such as GFR..F1F2/F2F7 and GFRN..F5F6 are primarily used as overrunning or indexing clutches.
Stieber Sprag Freewheels
Stieber manufactures both roller freewheels and sprag freewheels.
In a roller freewheel, rollers operate between the outer race and ramp geometry of the inner race. In a sprag freewheel, specially profiled sprags operate between cylindrical races to provide directional torque transmission.
The correct construction depends on the required operating function, speed, torque and installation conditions.
Centrifugally Lift-Off Stieber Freewheels
For demanding high-speed applications, Stieber offers a dedicated family of centrifugally lift-off sprag freewheels.
This group includes series such as:
RSCI, RSXM, RDBK, RSRV, RSRT, RIZ and RINZ, together with several RIZ configurations.
The RSCI range provides a good example. Stieber describes RSCI as a centrifugal lift-off sprag freewheel with a rotating inner race. It is primarily intended as a backstop but can also operate as an overrunning clutch in appropriate drive configurations.
Stieber Backstops
A backstop is used where reverse rotation of a machine shaft must be prevented.
During normal operation, the freewheel overruns. If the drive stops and the system attempts to rotate backwards, the freewheel engages and prevents reverse rotation.
Stieber's portfolio includes dedicated industrial backstop solutions such as BC MA, RDBK, RDBR-E, RSCI and RSRV/RSRT, depending on the required construction and operating conditions.
Self-Contained Stieber Freewheels
Stieber also offers complete self-contained assemblies including families such as AL/ALP, AV, BC MA, CEUS, GFR/GFRN configurations, RDBR-E, RSBW and SMZ.
For example, Stieber SMZ is a sealed, bearing-supported sprag-type freewheel. It uses two grease-lubricated 60..ZZ-series bearings and is supplied lubricated and ready for installation.
At the other end of the application spectrum, CEUS is a self-contained roller-type one-way clutch in a cast-iron housing, intended for high-power, high-speed dual or standby drives such as industrial fans, pumps and turbines.
How to Select a Stieber Freewheel
A Stieber freewheel should be identified using the complete manufacturer designation. Dimensions alone are not sufficient for confirming a replacement.
Selection should account for the required function — overrunning clutch, indexing clutch or backstop — together with torque, driving and overrunning speeds, direction of rotation, shaft and housing connection, bearing support, lubrication, sealing and installation conditions.
For this reason, references such as CSK, CSK..2RS, CSK..P, GFR, GFRN, RSCI, RIZ, AS, ASNU, AA and NFR should not be reduced to a generic “one-way bearing” description. Their construction and installation requirements differ substantially.
Stieber Product Identification
When replacing an existing Stieber component, record the complete marking from the installed unit.
A useful identification request should contain the exact Stieber reference, available dimensions, application and required operating function. If the original designation includes letters, numbers or suffixes, retain them exactly.
This is especially important for maintenance and MRO purchasing, where visually similar freewheels may have different connection methods or operating characteristics.
Stieber Products at simmering.pl
At simmering.pl, Stieber products can be searched by their exact manufacturer designation. For industrial maintenance and replacement applications, we recommend using the complete reference from the existing freewheel or technical documentation rather than selecting a product by dimensions alone.
Warehouse and Store: Lublin, Smoluchowskiego 1 Street, Building 4.
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FAQ – Stieber Freewheels and Backstops
What does Stieber manufacture?
Stieber specializes in freewheels, overrunning clutches and backstops for mechanical power-transmission systems. Its range includes roller and sprag constructions, built-in units, bearing/freewheel combinations and self-contained assemblies.
What is the difference between an overrunning clutch and a backstop?
An overrunning clutch disengages when the driven component rotates faster than the driving component. A backstop allows normal rotation in one direction but prevents reverse rotation.
What is a Stieber CSK?
CSK is a compact bearing/freewheel family. Stieber states that standard CSK mounting dimensions correspond to ball-bearing series 62. Different CSK suffixes identify different configurations.
Does Stieber manufacture sprag clutches?
Yes. Stieber offers sprag-type freewheels as well as roller-type designs. Its portfolio includes conventional and centrifugally lift-off sprag constructions.
Can two Stieber freewheels with the same dimensions be interchangeable?
Not automatically. The operating principle, torque capability, speed limits, mounting arrangement, lubrication, sealing and direction of rotation must also be compatible.
What information is needed to identify a Stieber replacement?
Start with the complete manufacturer reference from the original unit. Depending on the application, dimensions, function, torque, speed and installation details may also be required.
AI Overview
Stieber manufactures industrial freewheels, overrunning clutches, indexing clutches and backstops for mechanical drive systems. Its portfolio includes roller and sprag designs, built-in freewheels, CSK bearing/freewheel units, GFR modules, centrifugal lift-off systems and self-contained assemblies. Correct selection requires the complete Stieber designation and verification of function, torque, speed and mounting conditions.
SHORT DESCRIPTION
Stieber specializes in industrial freewheels, overrunning clutches, one-way clutches and backstops. The range includes built-in roller freewheels, sprag freewheels, CSK bearing/freewheel units, GFR/GFRN modules, RSCI and RIZ centrifugal lift-off designs and self-contained assemblies. Stieber freewheels can perform overrunning, indexing or backstopping functions. For correct replacement, always use the complete Stieber reference and verify the required function, torque, speed and mounting arrangement.