HG Hand Torque Multipliers – FAQ & User Guide

Quick Answer

The HG-Series is a line of manual torque multipliers designed to generate high torque output while requiring substantially less input torque from the operator.

Used in combination with a torque wrench, the multiplier's gearing increases the applied input torque according to the model's torque multiplication ratio. The HG-Series covers maximum outputs from 1,033 to 36,880 lbf.ft (1,400 to 50,000 N·m), making it suitable for precision tightening and loosening of heavy-duty fastening connections.

Because HG multipliers operate mechanically, they are particularly useful for field service and remote applications where compressed air or electricity is unavailable.

Who This Is For

Maintenance and repair technicians
Field service technicians
Heavy equipment technicians
Petrochemical facilities
Power generation facilities
Transportation and shipping operations
Mining operations
Industrial maintenance teams
Manufacturing and assembly operations
Applications involving large, high-torque fasteners

Mountz identifies petrochemical, power generation, transportation, shipping, and maintenance among common HG applications.

When Should You Use This?

Use an HG Hand Torque Multiplier when:

High torque is required but manual input needs to be reduced
Air or electricity is not readily available
Heavy-duty fasteners need to be tightened or loosened
A controlled alternative to impact-style fastening is preferred
Space limitations make other high-torque equipment difficult to use
Field or remote maintenance requires a mechanical torque solution
A torque wrench is available to provide controlled input torque
Torque requirements exceed the practical range of conventional hand torque wrenches

The HG-Series is specifically designed to combine relatively low input torque with high output torque through mechanical multiplication.

When Should You NOT Use This?

The HG may not be the best choice when:

Torque requirements can be comfortably handled with a conventional torque wrench
High-volume production requires faster powered fastening
Pneumatic or electric torque multipliers would provide better productivity
There is no suitable reaction point available
The reaction device cannot be safely positioned
Electronic fastening data collection or traceability is required
The application requires direct digital measurement of output torque

For repetitive high-torque production where power is available, a pneumatic or electric torque multiplier may be more appropriate.

How the HG Hand Torque Multiplier Works

The HG uses an internal gear system to multiply the torque supplied by a torque wrench.

During operation:

A torque wrench is connected to the multiplier's 3/4" female square input drive.
The appropriate impact socket is installed on the multiplier's output drive.
The reaction foot or reaction ring is positioned against a suitable reaction point.
The operator applies torque through the torque wrench.
The multiplier's gearing increases the input torque according to the model's torque multiplication ratio.
The reaction device counteracts the rotational force generated during operation.
The multiplied torque is delivered to the fastener.

All models use a 3/4" female square input drive, while output drive size varies by model.

Result:

High torque output with lower operator input
Controlled tightening and loosening
Reduced physical effort compared with applying the full torque directly
Mechanical operation without air or electricity
Greater capability for heavy-duty fastening applications

Core Features

Manual mechanical torque multiplier
Maximum torque output up to 36,880 lbf.ft (50,000 N·m)
Accuracy better than ±5%
Designed for use with a torque wrench
Low input torque produces high output torque
Compact construction for space-restricted applications
No air or electricity required
Quality steel construction
Most models feature anti-windup ratchets
Shear pin at the input drive protects the gearbox in an overload condition
Supplied with additional shear pins
Torque multiplication selection chart included
Reaction device supplied with each model

Available Models

The HG lineup includes 10 hand multiplier configurations, ranging from the H-10 through the HG-80.

Model	Item #	Maximum Output	Torque Multiplication Ratio	Gear Ratio	Output Drive
H-10	213700	1,033 lbf.ft / 1,400 N·m	3.5:1	4	3/4"
H-15	213701	1,033 lbf.ft / 1,400 N·m	3.5:1	4	1"
HG-10	213702	1,033 lbf.ft / 1,400 N·m	3.5:1	4	3/4"
HG-15	213703	1,033 lbf.ft / 1,400 N·m	3.5:1	4	1"
HG-20	213704	2,581 lbf.ft / 3,500 N·m	11.5:1	16	1"
HG-30	213705	3,687 lbf.ft / 5,000 N·m	14.3:1	18	1 1/2"
HG-40	213706	4,425 lbf.ft / 6,000 N·m	16:1	21	1 1/2"
HG-50	213707	5,900 lbf.ft / 8,000 N·m	20.5:1	24	1 1/2"
HG-60	213708	8,480 lbf.ft / 11,500 N·m	23.2:1	28	1 1/2"
HG-80	213709	36,880 lbf.ft / 50,000 N·m	126:1	180	2 1/2"

These specifications are listed in the HG product sheet's model and drive-size tables.

Important: H-10 and H-15 are listed in the HG product sheet, but the current Mountz product page notes that H-10 and H-15 do not feature Anti-Windup.

Model Selection Guide

If you need:	Recommended Model
Up to 1,033 lbf.ft with 3/4" output	H-10 or HG-10
Up to 1,033 lbf.ft with 1" output	H-15 or HG-15
Up to 2,581 lbf.ft	HG-20
Up to 3,687 lbf.ft	HG-30
Up to 4,425 lbf.ft	HG-40
Up to 5,900 lbf.ft	HG-50
Up to 8,480 lbf.ft	HG-60
Maximum HG torque capacity	HG-80

When selecting a model, consider the required output torque, output square drive, multiplication ratio, reaction device, available clearance, and physical size of the multiplier.

Understanding Torque Multiplication Ratio

Each HG model has a specified torque multiplication ratio.

For example, the HG-20 has an 11.5:1 multiplication ratio, while the HG-40 has a 16:1 ratio and the HG-80 has a 126:1 ratio.

The multiplication ratio is used to determine how much input torque is required to produce the desired output torque.

The actual input setting should be determined using the torque multiplication selection information supplied with the tool rather than assuming the nominal ratio alone provides the final wrench setting.

Each HG multiplier includes a torque multiplication selection chart for this purpose.

Anti-Windup Ratchet

Most HG models feature an anti-windup ratchet.

During high-torque multiplication, the multiplier's gearing can store rotational energy. The anti-windup mechanism helps manage this stored load during operation, allowing high-torque fastening work to be performed more efficiently.

Mountz specifically notes that H-10 and H-15 are not fitted with Anti-Windup.

The HG-80 is also identified in the uploaded HG product sheet as not fitted with Anti-Windup.

So I would describe the feature as "Most models feature an anti-windup ratchet", rather than applying it to the entire series.

Reaction Devices

A torque multiplier requires a reaction device to counteract the rotational force created as torque is applied.

The HG-Series is supplied with a reaction device based on the model:

H-10 through HG-60: Reaction Foot
HG-80: Reaction Ring

The HG product sheet specifically states that all models are supplied with a reaction foot except the HG-80, which is supplied with a reaction ring.

The reaction device must be positioned securely against a suitable reaction point before torque is applied.

Shear Pin Protection

The HG-Series uses a shear pin at the input drive to help protect the internal gearbox in the event of a torque overload.

If excessive input torque is applied, the shear pin is designed to protect the multiplier's gearing from the overload condition.

Each tool is supplied with extra shear pins.

Drive Sizes

All HG hand multipliers use a 3/4" female square input drive for connection to the torque wrench.

Output drive sizes vary according to model:

3/4": H-10 and HG-10
1": H-15, HG-15, and HG-20
1 1/2": HG-30, HG-40, HG-50, and HG-60
2 1/2": HG-80

Select sockets and accessories rated appropriately for the torque output of the multiplier.

Setup & Operation

Determine the required fastener torque.
Select an HG multiplier with sufficient torque capacity.
Select an appropriate torque wrench for the required input torque.
Determine the correct torque wrench setting using the multiplier's supplied torque multiplication selection chart.
Install the appropriate impact socket on the output square drive.
Position the multiplier on the fastener.
Position the reaction foot or reaction ring securely against a suitable reaction point.
Connect the torque wrench to the 3/4" female input drive.
Apply force smoothly to the torque wrench.
Continue until the required torque wrench setting is reached.
Follow the proper unloading procedure for the specific multiplier before removing the tool.

Because the multiplier generates substantial reaction force, correct reaction device positioning is critical during operation.

Accuracy & Torque Control

The HG-Series provides accuracy better than ±5%.

The multiplier is designed to operate in combination with a torque wrench. The torque wrench controls the input torque, while the HG's gearing multiplies that input to generate the required output.

For critical fastening applications, the torque wrench and multiplier system should be periodically verified according to the facility's torque control and quality procedures.

Common Applications

The HG-Series is commonly used in:

Petrochemical facilities
Power generation
Transportation
Shipping and marine operations
Heavy equipment maintenance
Industrial maintenance
Large machinery assembly
Field service
Remote maintenance locations
Heavy-duty bolting

The current HG product page specifically identifies petrochemical, power generation, transportation, shipping, and maintenance industries.

Use Cases (Real-World Examples)

Remote Field Maintenance

Problem: A technician needs to tighten or loosen a large fastener in an area where compressed air and electricity are unavailable.

Solution: The HG operates mechanically with a torque wrench, providing high torque output without requiring an external power source.

Heavy-Duty Bolting

Problem: A large industrial fastener requires substantially more torque than can practically be applied directly with a hand torque wrench.

Solution: The HG multiplies the wrench's input torque through its internal gearing, allowing the required output to be achieved with lower manual input.

Restricted Work Area

Problem: Space around a large fastening connection limits the use of larger powered bolting equipment.

Solution: The HG's compact mechanical design makes it suitable for certain space-restricted high-torque applications.

Extreme High-Torque Application

Problem: A heavy-duty connection requires torque well beyond the capacity of conventional hand torque tools.

Solution: The HG-80 provides maximum output up to 36,880 lbf.ft (50,000 N·m) with a 126:1 torque multiplication ratio and 2 1/2" output drive.

Maintenance

Keep the multiplier clean and free of contamination.
Inspect the input and output drives before use.
Inspect the reaction foot, reaction ring, and retention components for wear or damage.
Check the shear pin and replace it with the correct replacement if required.
Inspect the torque wrench used with the multiplier and maintain its calibration.
Use sockets rated for the required torque.
Periodically verify the multiplier's performance as part of the facility's torque control program.
Remove damaged or improperly functioning equipment from service until inspected or repaired.

Accessories

The HG product sheet identifies several accessories for the multiplier system.

6-Point Impact Sockets

A range of heavy-duty impact sockets is available for use with the multipliers.

Retention Ring

The retention ring holds a reaction foot, bar, or ring on the multiplier.

Reaction devices, sockets, and related components should be selected based on the multiplier model and fastening application.

Integration & Advanced Notes

Manual mechanical torque multiplier
Operates with a torque wrench
No compressed air or electrical power required
All models use a 3/4" female square input drive
Output drives range from 3/4" to 2 1/2"
Maximum output ranges from 1,033 to 36,880 lbf.ft
Torque multiplication ratios range from 3.5:1 to 126:1
Accuracy better than ±5%
Most models feature anti-windup ratchets
Shear pin protects the gearbox from overload
Steel construction
Reaction device supplied with each model
Torque multiplication selection chart supplied with each tool

Media & Supporting Content

Need Help?

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