Stieber

What Stieber does

Stieber GmbH is a German manufacturer of overrunning clutches, freewheels, backstops, and torque limiters, founded in 1937 in Munich by Edouard Stieber and headquartered today in Heidelberg with a secondary facility in Garching near Munich. The company designs and produces a broad range of roller-ramp and sprag-type one-way clutch technologies, organized into five product categories: built-in freewheels, centrifugally lift-off sprag freewheels, combined bearing freewheels, self-contained freewheels, and custom-engineered solutions. Its product portfolio spans torque capacities from 0.8 Nm to 1,700,000 Nm across more than 5,000 standard and custom designs, and includes differentiated IP such as the patented centrifugal lift-off sprag technology (RSBI/RSCI series) and the world's largest backstop, the "Dino" at 1,700,000 Nm, which was installed on the Selby coalfield conveyor in the UK in 1980. In-house testing capability extends to 700,000 Nm with bore testing up to 600mm at 1,500 rpm, supporting qualification for demanding applications.

Stieber serves industrial machinery, mining and aggregate, crane and hoist, marine, power generation (including nuclear primary cooling pumps), oil and gas, aerospace and defense, metal processing, food and beverage, and medical mobility customers. The company is approved to ISO 9001 (since 1997) and ISO 14001 (since 2000), and its product technical data is calculated using FVA methods (Forschungsvereinigung Antriebstechnik). Named reference customers include Rateau and AEG (nuclear primary cooling pumps, 1962 onward) and the Selby coalfield (mining conveyor backstops). The go-to-market blends direct sales from the German facilities with a global network of more than 1,000 stocking distributors and technical centers across 70+ countries. Pricing is project-based with one-time product sales and custom-engineering fees, and no public pricing is disclosed.

Since 2005, Stieber has been part of the Altra Industrial Motion group, and since 2023, it has been a subsidiary of Regal Rexnord following its acquisition of Altra. Within Regal Rexnord, Stieber operates alongside US sister companies Formsprag and Marland; together the three brands are positioned as the world's market leader for overrunning clutches and backstops, with Stieber serving as the European anchor. The company has approximately 140 employees at its German locations and is governed by Managing Directors Robert Rank and Kerry Gahm.

Name

Stieber

Legal name

STIEBER GmbH

Website

https://stieberclutch.com

Company type

Private

Founded year

1937

Operating status

Operating

Headcount range

51–100 employees

Short description

Stieber GmbH is a German manufacturer of overrunning clutches, freewheels, backstops, and torque limiters serving mining, power generation, marine, aerospace, and industrial machinery customers. Founded in 1937, it operates as the European market leader and a subsidiary of Regal Rexnord.

Ownership category

akta.pro rank

Product category

Industrial Clutches and Freewheels

NAICS

Speed Changer, Industrial High-Speed Drive, and Gear Manufacturing (333612)

SIC

General Industrial Machinery & Equipment (3560)

akta.pro primary industry

Brakes, Clutches & Couplings (Electromagnetic Brakes, Torque Limiters) (IMAGACAK)

akta.pro secondary industry

Linear Motion & Mechanical Power Transmission (Ball/roller screws, linear guides, bearings, couplings) (IMAHAGAM)

Keywords

• Overrunning clutches
• One-way freewheels
• Backstop clutches
• Sprag clutch technology
• Torque limiters

Headquarters

HQ city

Heidelberg

HQ country

Germany

HQ region

Europe

Offices2 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Personnel, Operations, Supply Chain, Technology or R&D, Marketing or Sales, Infrastructure

Revenue model

1. Overrunning Clutch Products: Sale of standard and custom overrunning clutches, sprag clutches, backstops, and torque limiters for mechanical engineering applications
2. Custom Engineering Solutions: Customized designs from small modifications to completely new parts with torque capacity from some Nm up to 1,700,000 Nm

Go-to-market motion2 records

Distribution channels2 records

Marketing channels2 records

Core offering

Stieber manufactures highly-engineered overrunning clutches, freewheels, backstops, and torque limiters for power transmission and one-directional rotation control in industrial applications. Products are based on roller-ramp and sprag-type one-way clutch technologies and span torque capacities from 0.8 Nm to 1,700,000 Nm across more than 5,000 standard designs and 3,000+ custom-engineered variants. The portfolio serves industrial machinery manufacturers and heavy-industry end users in mining, marine, power generation, oil & gas, crane & hoist, aerospace & defense, food & beverage, metal processing, and medical mobility segments.

Product overview

Stieber manufactures highly-engineered overrunning clutch technologies including freewheels and backstops. The product portfolio consists of five main categories: (1) Built-In Freewheels (AA, AE, AS, ASNU, DC, NF, NFR) - requiring customer-provided bearing support and lubrication; (2) Centrifugally Lift-Off Sprags Freewheels (RSCI, RSXM, RDBK, RSRV/RSRT, RIZ/RINZ) - featuring contact-free overrunning via centrifugal force; (3) Combined Bearing Freewheels (ASK, CSK/CSK2RS, CSKP) - self-contained units matching standard bearing dimensions; (4) Self-Contained Freewheels (AL/ALP, GFR/GFRN, AV, RSBW, CEUS, BC MA, FSO/FS/HPI, RDBR-E, SMZ) - complete units with integrated bearings and seals; (5) Custom Specific Solutions with over 5,000 special designs. Products transmit torque from 0.8 Nm to 1,700,000 Nm and serve markets including material handling, mining, marine, power generation, and industrial machinery.

Differentiator

Problem solved

Functional benefit

Products and services

• Built-In Freewheels Overrunning clutches delivered without bearings or seals for industrial customers who require customer-provided bearing support and lubrication. The product family comprises roller-type designs (AA, AE, AS, ASNU, NF, NFR) and sprag-type designs (DC), used as one-way clutches and backstops in mechanical drive systems.
• Centrifugally Lift-Off Sprags Freewheels Sprag-type freewheels with centrifugal lift-off mechanism enabling contact-free overrunning at speed. The family includes RSCI, RSXM, RDBK, RSRV/RSRT, and RIZ/RINZ series and is used primarily as high-speed backstops and overrunning clutches in multidrive and safety-critical applications.
• Combined Bearing Freewheels Freewheels with integrated bearings supplied as self-contained, grease-lubricated units matching standard ball bearing dimensions. The family includes ASK, CSK, CSK2RS, and CSKP series for one-way drive duties requiring compact dimensions and drop-in bearing replacement.
• Self-Contained Freewheels Complete freewheel units with integrated bearings, seals, and lubrication systems. The family includes AL/ALP, GFR/GFRN, AV, RSBW, CEUS, BC MA, FSO/FS/HPI, RDBR-E, and SMZ series for one-way drive, backstop, and torque-limiting duties across industrial applications.
• Custom Specific Solutions Custom-designed overrunning clutches, backstops, torque limiters, and indexing clutches engineered to specific customer requirements. More than 5,000 special designs are available, with torque capacity from 0.8 Nm to 1,700,000 Nm, ranging from small modifications of standard products to completely new parts.
• RDBK High Speed Backstop Centrifugal lift-off sprag RSCI high-speed backstop equipped with an integral torque limiter using a multi-disc brake working in oil for constant slip torque. Used in multidrive conveyor systems for load sharing between multiple drives.
• RDBR-E Roller Ramp Backstop Roller-type low-speed backstop with a fully bearing-supported multidisc brake for torque limiting/load sharing. Self-contained and oil-lubricated, with optional hydraulic or mechanical release function for conveyor maintenance, marketed as 'the Stieber RDBR-E limiting/load sharing low-speed backstop' that limits stresses and protects conveyor belt systems.
• RSCI 180-300 Series Sprag Freewheel Centrifugal lift-off sprag freewheel with rotating inner race in sizes 180-300. Non self-supported design requiring external bearing support, used as a backstop and overrunning clutch in crawl drives.
• RSCI 20-130 Series Sprag Freewheel Centrifugal lift-off sprag freewheel with rotating inner race in sizes 20-130. Non self-supported type requiring external bearings, accepting all common gearbox lubricants.
• RSRV/RSRT High-Speed Backstop Series Centrifugal lift-off sprag high-speed backstops with integral torque limiter. RSRV is the pure load-sharing version; RSRT features mechanical or hydraulic release under load for maintenance operations.
• CEUS Encased Roller Freewheel Encased roller-type freewheel from the CECON product group for high-speed overrunning. Self-contained in a cast iron housing with integrated forced lubrication for contact-free operation.
• CSK / CSK2RS Combined Bearing Freewheel Sprag-type freewheel integrated into a 62-series ball bearing footprint. Self-contained, grease-lubricated with dust protection; the CSK2RS variant features water-splash-resistant lip seals.
• ASK Series Combined Bearing Freewheel Bearing-supported roller-type freewheel with two rows of roller bearings. Self-contained, dust-protected, and grease-lubricated; dimensions match the 60-series bearing standard.
• AL / ALP Series Roller Freewheel Modules Roller-type freewheel basic modules designed for completion with flange and cover. Bearing-supported with two 160-series bearings, requiring oil lubrication.
• BC MA Roller Backstop Roller-type backstop, bearing-supported and self-contained, designed for conveyor drive pulley shafts in harsh environments. Symmetrical design with a single I-beam torque arm.
• AA Series Built-In Freewheel Roller-type freewheel with outer race connection via through screws. Non-bearing-supported design requiring external bearing support and lubrication.
• DC Series Double-Cage Sprag Freewheel Double-cage sprag freewheel cage without inner or outer races. Must be installed with customer-provided races, bearing support, lubrication, and sealing.
• GFR / GFRN Series Roller Freewheel Modules Roller-type freewheel basic modules; the GFRN variant features a keyway outer race connection. Both require completion with flange and cover for oil lubrication.
• SMZ Series Sprag Freewheel Bearing-supported sprag-type freewheel. Grease-lubricated with outer race connection via face screws; high-speed overrunning capability.
• FSO / FS / HPI Series Sprag Freewheel Sprag-type freewheels to the USA Formsprag design standard. Self-contained, sealed with two ball bearings, available in oil- or grease-lubricated versions for various industrial applications.

Quantifiable outcome

• Torque capacity range: 0.8 Nm to 1,700,000 Nm
• +1 more outcomes

Named customers3 records

Segments10 records

Ideal customer profiles2 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature8 records

Partnerships

Four partnerships are on record, tiered core and minor.

• FormspragcoreStrategic or Co-development PartnerSister company in the USA within Regal Rexnord Group. Together with Stieber and Marland, Formsprag forms the world's market leader for overrunning clutches and backstops.
• MarlandcoreStrategic or Co-development PartnerSister company in the USA within Regal Rexnord Group. Together with Stieber and Formsprag, Marland forms the world's market leader for overrunning clutches and backstops.
• Regal RexnordcoreStrategic or Co-development PartnerParent company of Stieber following acquisition of Altra Industrial Motion in 2023. Regal Rexnord is a major industrial motion company providing global infrastructure and resources.
• Altra Industrial MotionminorOthersStieber joined Altra Industrial Motion group in 2005. Altra was subsequently acquired by Regal Rexnord in 2023.

Scale indicators9 records

Recent moves8 records

Expansion highlights6 records

Direct peers

• Hilliard Corporation: US-based manufacturer of overrunning clutches, backstops, and sprag clutches serving similar industrial end markets. Direct niche competitor to Stieber outside the Regal Rexnord group.
• Marland Clutch: Sister company under Regal Rexnord; specializes in roller-type backstops and holdbacks for conveyors, directly overlapping with Stieber's BC MA series and broader backstop portfolio.
• Formsprag Clutch: Sister company under Regal Rexnord; manufactures sprag-type overrunning clutches and backstops with significant product overlap, serving similar customers in the Americas. The most direct comparable to Stieber.
• Nexen Group: US manufacturer of industrial clutches, brakes, and torque control products including overrunning and indexing clutches. Comparable in niche industrial clutch technology with overlapping applications.
• R+W Antriebselemente: German manufacturer of precision couplings and torque limiters; comparable engineering-driven niche player serving similar European industrial OEMs and competing with Stieber in mechanical power transmission components.

Broad incumbents

• BorgWarner: Global automotive and industrial supplier with deep clutch heritage (referenced as 'Borg-Warner standard' by Stieber for its 1968 sprag clutches). Broad incumbent in drivetrain components with indirect competition in industrial clutches.
• Tsubaki (Power Transmission): Japanese industrial conglomerate offering a broad power transmission portfolio including cam clutches, backstops, and chain drives. Overlaps with Stieber in overrunning clutches but at much greater scale and product breadth.
• Warner Electric: Also part of Regal Rexnord; manufactures electromagnetic clutches, brakes, and torque limiters with broader industrial coverage. Comparable in clutches/brakes category but with wider product breadth than Stieber's specialty.

Market position

Strengths4 records

Weaknesses4 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

• Xfacebook.com/RegalRexnordCorp
• YouTubeyoutube.com/channel/UCkfqZHN1Amu1AxB7eOnzYlw
• Facebookfacebook.com/stieberclutch
• LinkedInlinkedin.com/company/stieberclutch

Compliance3 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles3 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Stieber