Quick Answer
The CLS-Series is a line of fixed-body pneumatic torque multipliers designed for precision tightening and loosening of heavy-duty fastening connections.
The series is available in two configurations:
- Single Speed: Higher-speed operation for lower torque ranges
- Two Speed: Manual two-speed gearbox for controlled rundown and higher torque capacity
CLS multipliers operate with smooth, continuous, non-impacting rotation and shut off automatically when the preset torque is achieved. Torque output is controlled through the compressed air supply using a Lubro-Control Unit (LCU).
Across both configurations, the CLS-Series covers torque ranges from 44 lbf.ft to 12,540 lbf.ft, with the two-speed CLS2/4800 extending to 35,845 N·m.
Who This Is For
- Manufacturing engineers
- Maintenance technicians
- Field service technicians
- Heavy equipment technicians
- Power generation facilities
- Petrochemical facilities
- Transportation and shipping operations
- Industrial maintenance teams
- Heavy machinery manufacturing
- Applications requiring controlled high-torque bolting
When Should You Use This?
Use a CLS Pneumatic Torque Multiplier when:
- High-torque fastening is required
- Compressed air is available
- Faster fastening is needed than a hand torque multiplier can provide
- Smooth, non-impacting torque application is preferred
- Automatic shut-off at preset torque is required
- Heavy-duty fasteners need to be tightened or loosened
- Hydraulic wrench setup and ratcheting would reduce productivity
- Impact wrench vibration and hammering are undesirable
- Single-speed or two-speed operation is needed to match the application
The CLS is designed to improve bolting speed while maintaining controlled torque application.
When Should You NOT Use This?
The CLS may not be the best choice when:
- Compressed air is unavailable
- Portable manual operation is required
- Cordless operation is preferred
- A suitable reaction point cannot be established
- Electronic fastening data or torque traceability is required
- The available air supply cannot be properly filtered and regulated
- Torque requirements fall outside the CLS-Series ranges
For remote applications without a power source, consider an HG or MTM Hand Torque Multiplier.
How the CLS Pneumatic Torque Multiplier Works
The CLS uses a pneumatic motor and heavy-duty gearbox to generate controlled high torque.
During operation:
- The multiplier is connected to a filtered, regulated, and lubricated compressed air supply.
- The Lubro-Control Unit regulates air pressure to control torque output.
- The appropriate impact socket is installed on the square drive.
- The reaction device is securely positioned against a suitable reaction point.
- The operator activates the tool.
- The multiplier rotates the fastener smoothly without impact hammering.
- The tool automatically shuts off when the preset torque is reached.
Two-speed models also allow the operator to use a higher speed for rundown and switch to a lower speed for controlled high-torque tightening.
Result:
- Controlled high-torque fastening
- Faster bolting cycles
- Automatic shut-off
- Reduced vibration compared with impact tools
- Increased productivity
- Less operator effort than manual torque multiplication
Core Features
- Fixed-body pneumatic torque multiplier
- Accuracy better than ±5%
- Single-speed and two-speed configurations
- Automatic shut-off at preset torque
- Smooth, continuous, non-impacting rotation
- Torque controlled through the Lubro-Control Unit
- Heavy-duty gearbox
- Designed for precision tightening and loosening
- Compact design
- Multiple torque ranges and square drive sizes
- Faster operation than hydraulic torque wrenches
- Reduced hammering compared with impact wrenches
- Reaction foot, bar, and ring options
- Designed for heavy-duty industrial fastening
Configuration Options
| Configuration | Best For |
|---|---|
| Single Speed | Faster operation for lower to medium torque ranges |
| Two Speed | Higher torque capacity with separate rundown and tightening speeds |
Mountz describes the single-speed models as high-speed tools with a lower torque range, while the two-speed models use a manual two-speed gearbox for controlled tightening with higher torque ranges.
Single-Speed Models
Single-speed CLS models provide higher rotational speed and cover torque ranges from 44–162 lbf.ft up to 1,180–12,540 lbf.ft.
CLS Single-Speed Model Chart| Model | Item # | Torque Range | S.I. Range | Square Drive | Speed |
|---|---|---|---|---|---|
| CLS15 | 213030 | 44–162 lbf.ft | 60–220 N·m | 1/2" | 60 RPM |
| CLS15 | 213031 | 44–162 lbf.ft | 60–220 N·m | 3/4" | 60 RPM |
| CLS25 | 213032 | 70–206 lbf.ft | 95–280 N·m | 1/2" | 38 RPM |
| CLS25 | 213033 | 70–206 lbf.ft | 95–280 N·m | 3/4" | 38 RPM |
| CLS35 | 213034 | 99–287 lbf.ft | 135–390 N·m | 3/4" | 34 RPM |
| CLS45 | 213035 | 121–357 lbf.ft | 165–485 N·m | 3/4" | 27 RPM |
| CLS75 | 213036 | 225–660 lbf.ft | 305–895 N·m | 3/4" | 19 RPM |
| CLS95 | 213037 | 269–796 lbf.ft | 365–1,080 N·m | 3/4" | 13 RPM |
| CLS135 | 213038 | 365–1,069 lbf.ft | 495–1,450 N·m | 1" | 9 RPM |
| CLS175 | 213039 | 475–1,401 lbf.ft | 645–1,900 N·m | 1" | 7 RPM |
| CLS255 | 213040 | 671–1,969 lbf.ft | 910–2,670 N·m | 1" | 6 RPM |
| CLS315 | 213041 | 870–2,551 lbf.ft | 1,180–3,460 N·m | 1" | 4 RPM |
| CLS1700 | 213021 | 1,180–12,540 lbf.ft | 1,600–17,000 N·m | 2 1/2" | 1 RPM |
The CLS15 and CLS25 are each available with two square drive choices, providing more flexibility without changing torque range.
Two-Speed Models
Two-speed CLS models use a manual two-speed gearbox, providing a faster high-speed setting for rundown and a slower low-speed setting for controlled high-torque tightening.
CLS Two-Speed Model Chart| Model | Item # | Torque Range | S.I. Range | Square Drive | Low Speed | High Speed |
|---|---|---|---|---|---|---|
| CLS2/100 | 213001 | 88–830 lbf.ft | 120–1,125 N·m | 3/4" | 12 RPM | 36 RPM |
| CLS2/100 | 213002 | 88–830 lbf.ft | 120–1,125 N·m | 1" | 12 RPM | 36 RPM |
| CLS2/150 | 213014 | 125–1,191 lbf.ft | 170–1,615 N·m | 1" | 7 RPM | 21 RPM |
| CLS2/300 | 213003 | 284–2,651 lbf.ft | 385–3,595 N·m | 1" | 5 RPM | 15 RPM |
| CLS2/400 | 213004 | 398–3,728 lbf.ft | 540–5,055 N·m | 1 1/2" | 3 RPM | 9 RPM |
| CLS2/600 | 213006 | 620–5,800 lbf.ft | 840–7,865 N·m | 1 1/2" | 2 RPM | 6 RPM |
| CLS2/800 | 213008 | 745–6,960 lbf.ft | 1,010–9,435 N·m | 1 1/2" | 1.5 RPM | 5 RPM |
| CLS2/1000 | 213010 | 866–8,120 lbf.ft | 1,175–11,010 N·m | 1 1/2" | 1 RPM | 4 RPM |
| CLS2/4800 | 213005 | 3,466–35,845 lbf.ft | 4,700–48,600 N·m | 2 1/2" | 0.3 RPM | 0.6 RPM |
The two-speed configuration is especially useful when fast rundown is needed before transitioning to slower, controlled final tightening.
Model Selection Guide
| If you need: | Recommended Configuration |
|---|---|
| Lowest CLS torque range | CLS15 |
| High-speed lower-torque fastening | Single-Speed CLS |
| Up to approximately 800 lbf.ft | CLS95 or CLS2/100 |
| Torque above 1,000 lbf.ft | CLS135 or higher |
| Faster rundown plus controlled final tightening | Two-Speed CLS |
| Torque up to 12,540 lbf.ft | CLS1700 |
| Torque beyond single-speed capacity | CLS2-Series |
| Maximum CLS torque capacity | CLS2/4800 |
| 1/2" square drive | CLS15 or CLS25 configurations |
| 2 1/2" square drive | CLS1700 or CLS2/4800 |
Lubro-Control Unit (LCU)
The CLS uses the LCU-2 Lubro-Control Unit to manage the compressed air supplied to the multiplier.
The LCU provides:
- Filtered compressed air
- Regulated air pressure
- Lubricated air
- Controlled air supply for torque adjustment
Torque output is set by regulating air pressure according to the appropriate torque settings for the selected CLS model.
Mountz also specifies that pneumatic torque multipliers should use a high-quality air filter regulator.
Automatic Shut-Off
CLS multipliers automatically shut off when the preset torque is reached.
This provides:
- More consistent fastening
- Controlled torque application
- Reduced operator dependence
- Prevention of unnecessary continued rotation
- Improved productivity for repetitive bolting
The tool operates with continuous rotation rather than impact hammering.
Single Speed vs. Two Speed
Single-Speed CLS
Best when:
- Higher tool speed is the priority
- Torque requirements fall within the single-speed range
- Simple operation is preferred
- Repetitive bolting requires efficient rundown
Two-Speed CLS
Best when:
- Higher torque capacity is required
- Fast rundown and controlled final tightening are both important
- Large fasteners require longer rundown distances
- Greater flexibility in rotational speed is needed
The two-speed gearbox allows operators to perform the initial rundown faster and then switch to a lower speed as the joint approaches final torque.
Reaction Devices
A reaction device is required to counteract the force produced by the multiplier during operation.
Available reaction device types include:
- Reaction Foot
- Reaction Bar
- Reaction Ring
The CLS product literature states that all models are supplied with a reaction foot except models marked with an asterisk, which are supplied with a reaction ring.
The CLS1700 and CLS2/4800 are marked as supplied with reaction rings.
Setup & Operation
- Determine the required fastener torque.
- Select a CLS model with a torque range that includes the required value.
- Choose single-speed or two-speed operation based on the torque and productivity requirements.
- Connect the CLS to the LCU-2.
- Connect the LCU to a clean compressed air supply.
- Set air pressure according to the torque setting information for the selected model.
- Install an impact-rated socket on the square drive.
- Position the multiplier on the fastener.
- Position the appropriate reaction device securely against a suitable reaction point.
- For two-speed models, select the appropriate gearbox speed.
- Activate the multiplier.
- Allow the tool to operate until it automatically shuts off at the preset torque.
- Release the tool before moving to the next fastener.
Accuracy & Torque Control
The CLS-Series provides accuracy better than ±5%.
Torque output is regulated through air pressure supplied by the LCU rather than through a hand torque wrench.
For critical bolting applications, periodically verify output according to the facility's quality and torque control procedures.
CLS vs. CLD Pneumatic Torque Multipliers
Both CLS and CLD multipliers provide pneumatic high-torque fastening with automatic shut-off, but the body design differs.
| Feature | CLS | CLD |
|---|---|---|
| Tool Design | Fixed Body | Rotating Body |
| Power Source | Compressed Air | Compressed Air |
| Automatic Shut-Off | Yes | Yes |
| Continuous Rotation | Yes | Yes |
| Single-Speed Options | Yes | Yes |
| Two-Speed Options | Yes | No |
| 360° Rotating Handle | No | Yes |
| Best For | Broad torque range and two-speed flexibility | Flexible handle positioning |
Choose the CLS when fixed-body operation and the option for two-speed gearing are important.
Choose the CLD when a rotating body and 360° handle positioning provide better access or ergonomics.
Common Applications
The CLS-Series is commonly used in:
- Power generation
- Petrochemical facilities
- Heavy equipment maintenance
- Structural bolting
- Industrial machinery
- Transportation
- Shipping and marine operations
- Manufacturing
- Field service
- Large flange and bolted connections
- Heavy-duty maintenance
Use Cases (Real-World Examples)
Repetitive Heavy-Duty Bolting
Problem: Large numbers of high-torque fasteners make manual torque multiplication slow and physically demanding.
Solution: The pneumatic CLS provides continuous powered rotation and automatic shut-off, improving bolting speed and reducing operator effort.
Two-Speed Tightening
Problem: Large fasteners require significant rundown before final torque is reached.
Solution: CLS two-speed models provide a high-speed setting for rundown and a low-speed setting for controlled final tightening.
Alternative to Impact Wrenches
Problem: Impact wrench hammering creates vibration and operator fatigue.
Solution: The CLS uses smooth, continuous rotation instead of impact hammering, improving ergonomics during high-torque fastening.
Alternative to Hydraulic Torque Wrenches
Problem: Hydraulic equipment requires more setup and uses a slower ratcheting process.
Solution: The CLS provides continuous pneumatic rotation to improve productivity and reduce setup compared with hydraulic bolting systems.
Extreme High-Torque Applications
Problem: Very large industrial bolted connections require torque well beyond the range of conventional torque tools.
Solution: The CLS2/4800 provides up to 35,845 lbf.ft (48,600 N·m) with a 2 1/2" square drive.
Maintenance
- Use clean, filtered, regulated, and lubricated compressed air.
- Inspect air hoses and connections for wear or leaks.
- Inspect the square drive and gearbox for damage.
- Inspect reaction devices before operation.
- Keep the multiplier clean and free of contamination.
- Use impact sockets rated for the required torque.
- Inspect and maintain the LCU and air regulator.
- Follow manufacturer service intervals for the pneumatic motor and gearbox.
- Periodically verify torque output according to facility procedures.
- Remove damaged or improperly functioning tools from service until inspected or repaired.
Compatible Accessories
LCU-2 Lubro-Control Unit
Provides filtered, regulated, and lubricated compressed air and supports torque adjustment through air pressure.
Reaction Devices
Available styles include:
- Reaction Foot
- Reaction Bar
- Reaction Ring
Impact Sockets
Use impact-rated sockets sized and rated appropriately for the selected CLS model and application.
Media & Supporting Content
- CLS Pneumatic Torque Multiplier Product Page
- CLS Product Data Sheet
- CLS Operating Instructions
- LCU-2 Lubro-Control Unit
- Reaction Devices
- Impact Sockets
Related Content
- Hand Torque Multipliers
- Electric Torque Multipliers
- Radial Gearing Torque Multipliers
- Guide: Enhancing Quality in Heavy-Duty Manufacturing and Repair with a Torque Multiplier
- Guide: Choosing the Right Torque Multiplier
- Safeguarding Industrial Operations: The Importance of Torque Tools in Large Asset Maintenance
- Mountz Consolidated Tools Sales Bang Sheet
Need Help?
- Contact Applications Engineering for setup guidance
- Speak with Sales for product selection
- Call us:
- North America:(408) 850-9978
- International: +44 1428 741756
M-F 6am - 5pm PST
