Find the Right Clutch for Backstopping, Indexing or Overrunning
Carry loads in one direction with our large product line of one-way freewheel sprag clutches.
Complete Sprag Clutch Units
Designed for big loads that require lots of torque. These sprag clutches are the most robust in our product line.
Ball Bearing Sprag Clutch
Our most economical line of clutches. Good for low & medium torque demands. Sizes are matched to radial bearings.
Sprag Clutch Element
Two options: Sprag elements w/ rings for non-hardened mating parts & Sprag elements w/out rings for hardened & ground mating parts. External radial bearing support required.
What is a Sprag Clutch?
A one-way sprag clutch, sometimes called a “freewheel clutch,” allows rotation in one direction and instantly prevents force from being driven in the opposite direction.
Our GMN one-way sprag clutch products have a very compact design that maximizes the absorption of torque.
Find the right clutch for backstopping, indexing or overrunning with our large inventory of one-way freewheel sprag clutches.
Sprag clutch clamping.
Modes of Operation
Backstop Clutch
A backstop clutch is commonly used for safety precautions.
If a machine is designed to carry heavy objects, the backstop clutch is needed to hold the weight if the machine doesn’t function properly. A common example would be if the power goes out in an elevator. A backstop clutch can hold the weight in place & protect the people it’s carrying.
View our Backstop Clutch page to get more details and machine application examples.
Indexing Clutch
An indexing clutch pushes motion in a circular direction and then allows it to idle or stop. The most common example is an assembly line or automatic production line.
View our Indexing Clutch page to get more details and machine application examples.
Overrunning Clutch
This type of clutch application prevents force from being pushed in the reverse direction. An overrunning clutch allows idle rotation without engagement of force and permits the driven shaft of a machine to freewheel.
View our Overrunning Clutch page to get more details and machine application examples.
Our Sprag Clutch Product Line
Complete Sprag Clutch Units
These complete clutch units are designed with roller bearings and ball bearings making it the most powerful sprag clutch in our product line. This clutch is great for machines that require a heavy load and high torque.
Stats at a Glance
- Clutch Width (mm): 27 (open) or 34 (sealed)
- Operating Temperature: 212°F (100°C) or 284°F (140°C)
- ID Size Range (mm): 10 to 60
- OD Size Range (mm): 31 to 110
- Torque (Nm): 60 to 588
- Inner Ring: Press Fit and/or Keyway
- Outer Ring: Press fit and/or Mounting Tab
- Bearing Style: Integrated Ball and Roller Bearings
- Lubrication: Oil or Grease
- Seals: Rubber Seals or No Seals
Ball Bearing Sprag Clutch Units
Most Popular Clutch Line
These sprag clutch units are economical and are designed with ball bearings only, not roller bearings like the complete units above. The sizes offered are the same as our Series 6200 radial ball bearings. This product line is a good choice for small to medium torque requirements.
Stats at a Glance:
- Clutch Width (mm): 12 to 18
- Operating Temperature: 284°F (140°C) or on request, 338°F (170°C)
- ID Size Range (mm): 17 to 40
- OD Size Range (mm): 40 to 80
- Torque (Nm): 53 to 267
- Inner Ring: Press Fit and/or Keyway
- Outer Ring: Press fit and/or Keyway
- Bearing Style: Integrated Ball Bearing
- Lubrication: Grease
- Seals: Rubber Seals or No Seals
Sprag Clutch Element
This one-way clutch line consists of the sprag component from our complete sprag clutch units and can come with hardened and ground rings if needed.
The sprag clutch element components consist of a cage, a spring and a size dependent number of sprags.
Stats at a Glance:
- Clutch Width (mm): 7 or 12
- Operating Temperature: Max 338°F (170°C)
- ID Size Range (mm): 2 to 240
- OD Size Range (mm): 10 to 236
- Torque (Nm): 4 to 14,060
- Inner Ring: Press Fit and/or Keyway
- Outer Ring: Press fit
- Bearing Style: N/A
- Lubrication: Oil or Grease
- Spring Types: Tension or Meander
- Cage Material: Steel or Plastic
Top Resources & Guides for One-Way Sprag Clutches
- How Does A Sprag Clutch Work?
- How an Overrunning Clutch Works
- Lubricating a Sprag Clutch: Best Practices
- Three Stopping Options for a One-Way Sprag Clutch
How to Select the Right Sprag Clutch for Your Mode of Operation
Before selecting your clutch, you need to know a few key pieces of information.
- What’s driving the force? Electric motor, engine, etc.
- How will you be using the clutch? Backstopping, overrunning or indexing?
- How much torque will be transmitted/needed?
- What is your shaft diameter or bore size?
- Environment temperature while in operation.
- Will you need grease or oil lubrication?
Frequently Asked Questions About Sprag Clutches
How Do Sprag Clutches Work?
Insert elements are the components inside a sprag clutch and contain a cage, sprags and a spring.
The number of sprags in an insert element is determined by the size of the shaft. The spring preloads the friction between those sprags and parts.
These insert elements are not self centering and require additional bearing support for proper function, which both our complete sprag units and ball bearing units provide.
What are the benefits of buying one-way sprags from GMN?
The design of our GMN sprag clutches offers some key benefits for our customers:
- Our clutches are manufactured with small sprags which makes them light, compact (space-saver) and allows high indexing frequencies.
- Optimized design of the clamping curve allow our sprags to operate with high production and indexing accuracy.
Why Buy From GMN Bearing USA?
The success of our business comes from three main pillars of excellence:
- Rapid Response: 99% of inquiries are responded to within one business day and most orders ship out the same day (from Houston, Texas).
- Expert-Level Support: Our onsite mechanical engineers and technical support specialists provide answers to your most difficult questions.
- Quality 360°: Our internal quality control process is one of the highest in the industry. We make sure GMN is synonymous with quality.
Need help finding the right product for your application? Contact us today.