EFW Electric Torque Multipliers

Mountz EFW Electric Torque Multipliers provide a fast, accurate, and repeatable solution for tightening and loosening heavy-duty fastening connections in applications where overhead clearance is limited. Featuring a 90-degree right-angle drive, the EFW Series delivers smooth, continuous, non-impacting rotation, automatically reduces speed as it approaches the target torque, and shuts off when the preset torque is reached. With four models covering 663–7,228 lbf.ft (900–9,800 N·m), the EFW Series is ideal for industrial bolting applications requiring high torque in confined work areas.

Quick Answer

The EFW Series is a family of right-angle electric torque multipliers designed for controlled tightening and loosening of heavy-duty fastening applications where a traditional inline multiplier cannot be used because of limited working space.

Powered by a brushless synchronized electric motor, the EFW provides smooth, continuous, non-impacting rotation and automatically shuts off when the preset torque is reached. The integrated microprocessor controller manages torque, motor speed, and shut-off without requiring a separate external controller.

The EFW Series includes four models covering an overall torque range of 663–7,228 lbf.ft (900–9,800 N·m). All models feature a 1½-inch square drive and are designed to provide the same controlled fastening performance as the EF Series while offering improved accessibility in confined spaces.

Who This Is For

Manufacturing engineers
Maintenance technicians
Field service technicians
Heavy equipment manufacturers
Wind energy maintenance crews
Oil and gas operations
Power generation facilities
Industrial maintenance departments
Steel fabrication facilities
Applications requiring high torque with limited overhead clearance

When Should You Use This?

Use the EFW Electric Torque Multiplier when:

High-torque fastening is required
Working space prevents the use of an inline torque multiplier
AC electrical power is available
Smooth, continuous torque application is preferred
Automatic shut-off at the preset torque is required
Large industrial fasteners require controlled tightening
Hydraulic wrench setup would reduce productivity
Impact wrench vibration and hammering are undesirable
Improved access around machinery or structural components is needed
Repeatable torque is required across multiple fastening cycles

The EFW Series combines the performance of the EF Electric Torque Multiplier with a compact right-angle drive, making it easier to access applications where overhead clearance or surrounding equipment limits the use of an inline tool.

When Should You NOT Use This?

The EFW may not be the best choice when:

Electrical power is unavailable
A cordless solution is required
Compressed air is the preferred power source
A suitable reaction point cannot be established
Torque requirements fall outside the EFW operating range
Electronic fastening traceability or data collection is required
An inline multiplier provides sufficient access
The application involves drilling or mixing
The standard tool will be used in wet or explosive environments

The EFW is specifically designed for tightening and loosening threaded fasteners. It should never be used as a drill, mixer, pry bar, or for applications outside its intended purpose.

If sufficient overhead clearance is available, the inline EF Electric Torque Multiplier may be a better option. For applications without electrical power, consider a Mountz Hand Torque Multiplier or Pneumatic Torque Multiplier.

How the EFW Electric Torque Multiplier Works

The EFW uses a brushless synchronized electric motor and a heavy-duty planetary gearbox to generate controlled high torque. Unlike the inline EF Series, the EFW incorporates a 90-degree right-angle drive, allowing the multiplier to operate in locations with restricted overhead clearance.

During operation:

Install the appropriate socket onto the square drive.
Install the reaction device.
Position the reaction device against a secure reaction point.
Select the required torque setting.
Select the direction of rotation.
Activate the tool.
The multiplier rapidly runs down the fastener.
The motor automatically reduces speed as the preset torque is approached.
Once the target torque is reached, the motor shuts off automatically.

The controlled slowdown improves fastening accuracy while eliminating the hammering associated with impact tools.

Result

Controlled high-torque fastening
Automatic shut-off at the preset torque
Smooth, non-impacting rotation
Improved access in confined spaces
Faster bolting cycles
Reduced operator fatigue
Improved fastening consistency
No external controller required

Core Features

Right-angle electric torque multiplier
Brushless synchronized electric motor
Built-in microprocessor controller
Automatic shut-off at preset torque
Smooth, continuous, non-impacting rotation
Reduced speed before final shut-off
Accuracy better than ±5%
CW and CCW operation
LED torque display
19 selectable torque stages
Overheat protection
Universal power input (100–253 VAC, 45–66 Hz)
Compact 90-degree drive configuration
1½-inch square drive
Operating speeds from 3–8 RPM
Torque capacities up to 7,228 lbf.ft
No external controller box required
Remote-control operation available
All-weather versions available
Supplied with a reaction foot

EFW Electric Torque Multiplier Models

The EFW Series includes four right-angle models designed for applications requiring high torque in confined work areas. As torque capacity increases, operating speed decreases to provide greater torque output while maintaining controlled fastening performance.

Available Models

Model	Item #	American Torque Range	S.I. Torque Range	Metric Torque Range	Square Drive	Speed
EFW400	210618	663–3,134 lbf.ft	900–4,250 N·m	91.8–433.5 kgf.m	1½"	8 RPM
EFW600	210619	811–4,536 lbf.ft	1,100–6,150 N·m	112.2–627.6 kgf.m	1½"	7 RPM
EFW800	210620	1,327–5,752 lbf.ft	1,800–7,800 N·m	183.6–795.6 kgf.m	1½"	4 RPM
EFW1000	210621	1,512–7,228 lbf.ft	2,050–9,800 N·m	209.1–999.6 kgf.m	1½"	3 RPM

The EFW400 provides the highest operating speed at 8 RPM, while the EFW1000 delivers the highest torque capacity at 7,228 lbf.ft.

Model Selection Guide

If you need:	Recommended Model
Highest operating speed	EFW400
Torque up to approximately 3,100 lbf.ft	EFW400
Torque up to approximately 4,500 lbf.ft	EFW600
Torque up to approximately 5,700 lbf.ft	EFW800
Maximum torque capacity	EFW1000
Right-angle access for confined spaces	Any EFW model

Select a model whose operating range includes the required fastening torque while considering available working space, reaction point location, operating speed, and application requirements.

Torque Capacity vs. Operating Speed

As the EFW Series torque capacity increases, operating speed decreases. This allows each model to deliver higher torque while maintaining controlled fastening performance.

Model	Maximum Torque	Operating Speed
EFW400	3,134 lbf.ft	8 RPM
EFW600	4,536 lbf.ft	7 RPM
EFW800	5,752 lbf.ft	4 RPM
EFW1000	7,228 lbf.ft	3 RPM

Choose a Faster Model When:

Shorter fastening cycles are important.
The required torque falls within the lower EFW ranges.
Productivity is a higher priority than maximum torque capacity.
The application involves repetitive fastening.

Choose a Higher-Capacity Model When:

Large structural fasteners require greater torque.
The application exceeds the capacity of the EFW400 or EFW600.
Maximum torque output is more important than operating speed.
Heavy industrial bolting is being performed.

LED Display & Torque Settings

The EFW Series uses an LED display to indicate the selected torque stage and direction of rotation.

The display provides:

10 primary torque settings
9 intermediate torque settings
19 total selectable torque stages
Clockwise (CW) and counterclockwise (CCW) direction indication

The numbered stages correspond to the torque values listed in the torque chart supplied with each model. Intermediate torque values are indicated when two LEDs illuminate simultaneously.

Operators can use the controls to:

Increase the torque setting
Decrease the torque setting
Select clockwise or counterclockwise rotation
Confirm the selected direction
Start the fastening cycle
Stop the tool if necessary

Automatic Shut-Off

The EFW automatically shuts off when the preset torque is reached.

Unlike an impact wrench, which continues hammering until the trigger is released, the EFW monitors torque throughout the fastening cycle.

As the multiplier approaches the target torque:

Operating speed automatically decreases.
Final tightening is completed under greater control.
The motor shuts off automatically at the preset torque.

This provides several advantages:

Improved fastening consistency
Reduced risk of over-tightening
Greater repeatability
Less dependence on operator judgment
Reduced operator fatigue
Increased productivity during repetitive fastening

Built-In Controller & Brushless Motor

The EFW Series features a brushless synchronized electric motor controlled by an integrated microprocessor.

Unlike many electric torque systems, the EFW does not require a separate controller box.

The built-in controller manages:

Motor speed
Torque output
Electrical frequency
Automatic shut-off
Overheat protection

The brushless motor design also reduces routine maintenance while providing reliable performance during continuous industrial operation.

Universal Power Input

The EFW is designed for worldwide operation and accepts:

Voltage: 100–253 VAC
Frequency: 45–66 Hz

This wide operating range allows the tool to be used throughout many international markets without requiring different motor configurations.

Before operation:

Verify the available voltage matches the tool requirements.
Inspect the power cord and plug.
Confirm all electrical connections are secure.
Use only properly rated extension cords when required.
Disconnect the tool before installing accessories.

The standard EFW should not be operated in wet environments. All-weather configurations are available for applications requiring additional environmental protection.

Right-Angle Configuration

Unlike the inline EF Series, the EFW features a 90-degree right-angle gearbox that provides improved access to fasteners in confined work areas.

The right-angle configuration is ideal for applications where surrounding equipment or limited overhead clearance prevents the use of a traditional inline torque multiplier.

Benefits include:

Improved access around machinery
Better clearance in confined work areas
Easier positioning around structural components
High-torque fastening without sacrificing accessibility
Smooth, continuous, non-impacting operation
Automatic shut-off at the preset torque

The right-angle design makes the EFW particularly well suited for heavy industrial equipment, power generation systems, wind turbines, and maintenance applications where space is limited.

Reaction Device

Every EFW Electric Torque Multiplier requires a reaction device to absorb the rotational force generated during tightening or loosening.

Each tool is supplied with a reaction foot that installs near the square drive.

A proper reaction setup should:

Rest against a secure reaction point.
Remain level with the socket whenever possible.
Prevent the multiplier from rotating.
Keep the tool aligned with the fastener.
Avoid unstable or angled contact surfaces.

Never place your hands on the reaction device while the tool is operating. As torque builds, the reaction arm can move suddenly and may cause serious injury.

Setup & Operation

Before using the EFW:

Determine the required fastening torque.
Select the appropriate EFW model.
Verify the available electrical supply.
Disconnect power before installing accessories.
Inspect the multiplier, reaction device, socket, and adapters.
Install the reaction device.
Install the appropriate socket.
Secure all accessories.
Connect the tool to the power supply.
Select the desired torque stage.
Select the rotation direction.
Position the socket completely over the fastener.
Place the reaction device against a stable reaction point.
Keep the multiplier aligned with the fastener.
Start the fastening cycle.
Allow the tool to automatically stop at the preset torque.
Reverse briefly, if necessary, to release the reaction device.
Disconnect power before changing sockets or accessories.

Always inspect the tool before each use. Never operate the multiplier with damaged sockets, adapters, or reaction devices.

Tool Alignment & Safe Operation

Proper alignment is essential for accurate torque application and safe operation.

During use:

Fully seat the socket on the fastener.
Keep the multiplier aligned with the fastener axis.
Position the reaction device against a solid support.
Keep hands away from the reaction arm.
Never operate the tool if the reaction device can slip.

Improper alignment can result in:

Damaged sockets
Damaged square drives
Fastener damage
Gearbox damage
Reduced torque accuracy
Unsafe operating conditions

Once the preset torque has been reached, the motor automatically stops. If necessary, briefly reverse the tool to release pressure from the reaction device before moving to the next fastener.

Calibration & Accuracy

The EFW Series is designed to provide controlled, repeatable high-torque fastening with an accuracy of better than ±5% under specified operating conditions.

To maintain performance and accuracy:

Periodically verify torque output using appropriate torque testing equipment.
Recalibrate the multiplier approximately every 25 operating hours, or according to your facility's quality program.
Inspect the tool if torque output becomes inconsistent or if damage is suspected.
Have the multiplier serviced by qualified personnel using approved replacement parts.

The operating manual also recommends a complete inspection at least once per year or after approximately 1,000 operating hours, including:

Power check
Motor inspection
Safety inspection
General functional inspection

Common Applications

The EFW Series is commonly used in:

Wind turbine assembly and maintenance
Wind turbine gearbox installation
Oil and gas pipelines
Offshore drilling platforms
Power generation facilities
Heavy equipment manufacturing
Heavy equipment maintenance
Structural steel construction
Large flange tightening
Mining equipment
Industrial machinery
Confined maintenance applications
High-torque bolting where overhead clearance is limited

Use Cases (Real-World Examples) Confined Machinery Maintenance

Problem: Large fasteners are located inside machinery where overhead clearance prevents the use of an inline torque multiplier.

Solution: The EFW's right-angle configuration provides improved access while delivering controlled, repeatable high-torque fastening.

Wind Turbine Assembly

Problem: Wind turbine assemblies require consistent high torque while working around structural components that restrict tool access.

Solution: The EFW combines powered torque output with a compact right-angle design, allowing technicians to reach difficult fastening locations without sacrificing performance.

Pipeline & Refinery Maintenance

Problem: Large flange bolts require controlled tightening during maintenance shutdowns, but surrounding piping limits available working space.

Solution: The EFW delivers smooth, continuous torque through its right-angle drive, eliminating the need for hydraulic pumps while improving accessibility.

Alternative to Hydraulic Torque Wrenches

Problem: Hydraulic torque wrenches require pumps, hoses, setup time, and repeated ratcheting cycles.

Solution: The EFW provides a self-contained electric solution with continuous rotation, automatic shut-off, and improved access in confined work areas.

Alternative to Impact Wrenches

Problem: Impact tools create vibration, noise, and inconsistent final torque.

Solution: The EFW applies smooth, continuous torque and automatically shuts off at the preset value without impact hammering.

Repetitive High-Torque Production

Problem: Repeated high-torque fastening can be physically demanding and time-consuming with manual torque multipliers.

Solution: The EFW reduces operator effort while improving productivity through powered, repeatable torque application.

EFW vs. EF vs. Pneumatic vs. Hydraulic vs. Hand Torque Multipliers

Feature	EFW Electric	EF Electric	Pneumatic Multiplier	Hydraulic Torque Wrench	Hand Torque Multiplier
Configuration	Right-Angle	Inline	Inline	Inline	Inline
Power Source	AC Electricity	AC Electricity	Compressed Air	Hydraulic Pump	Manual
Continuous Rotation	✔	✔	✔	No	No
Automatic Shut-Off	✔	✔	Model Dependent	System Dependent	No
External Equipment Required	Power Cord	Power Cord	Air Compressor	Pump & Hoses	Torque Wrench
Best For	Tight clearance applications	Open work areas	Facilities with compressed air	Ultra-high torque bolting	Portable field work

Choose the EFW When:

Working space is limited.
Overhead clearance prevents the use of an inline tool.
Electrical power is available.
Automatic shut-off is required.
Smooth, continuous torque application is preferred.

Choose the EF When:

An inline configuration provides sufficient access.
Maximum operating speed is desired.
Working space is not restricted.

Choose a Pneumatic Torque Multiplier When:

Compressed air is readily available throughout the facility.
Pneumatic tools are already the plant standard.

Choose a Hydraulic Torque Wrench When:

Extremely high torque applications require hydraulic equipment.
Existing hydraulic infrastructure is already available.

Choose a Hand Torque Multiplier When:

Electrical power is unavailable.
Portability is the highest priority.
Fastening frequency is relatively low.

Maintenance

Proper maintenance helps maximize tool life and maintain fastening accuracy.

Regular maintenance should include:

Keeping the multiplier clean and dry.
Inspecting the power cord before each use.
Inspecting sockets, adapters, and reaction devices.
Checking the square drive for wear.
Inspecting all fasteners and safety hardware.
Periodically verifying torque output.
Recalibrating according to your facility's calibration schedule.
Removing damaged tools from service immediately.

Never:

Carry the tool by the power cord.
Operate with damaged accessories.
Use damaged sockets or adapters.
Attempt unauthorized repairs.

Electrical repairs should only be completed by authorized service personnel using approved replacement parts.

Compatible Accessories

The EFW Series is compatible with a variety of accessories to support different fastening applications.

Reaction Devices

Reaction devices absorb the rotational force produced during fastening and provide a stable reaction point.

Impact Sockets

Use sockets that:

Match the fastener size.
Match the 1½-inch square drive.
Are rated for the required torque.
Fully engage the fastener.
Are free from wear or damage.

Adapters & Connectors

Application-specific adapters and connectors can be used when additional reach or specialized configurations are required.

Retention Hardware

Retention rings and locking hardware help secure the reaction foot and accessories during operation.

Remote Control

Remote-control operation is available for applications where the operator needs to activate the tool from a position away from the fastener.

All-Weather Configuration

All-weather models are available for applications exposed to rain or damp conditions, providing additional environmental protection.

EFW Electric Torque Multipliers – FAQ & User Guide