Insulated Torque Wrenches – FAQ & User Guide

Quick Answer

Mountz Insulated Torque Wrenches are adjustable click torque wrenches designed for electrical fastening applications where both controlled torque and electrical protection are required.

The wrenches feature nonconductive insulation and are designed for use on electrical systems up to 1,000 volts. They provide an audible and tactile click when the selected torque is reached, helping operators apply the required torque while reducing the possibility of shorting or shock.

The current lineup includes two models, both covering 40–180 lbf.in (4–20 N·m). The primary difference is drive size: the SLO1/4I uses a 1/4" square drive, while the SLO3/8I uses a 3/8" square drive.

Who This Is For

Electrical assembly technicians
Manufacturing engineers
Process engineers
Quality engineers
Maintenance technicians
Battery assembly operations
Electrical equipment manufacturers
Industrial electrical assembly
Applications involving electrically live systems
Production environments requiring both torque control and electrical insulation

When Should You Use This?

Use an Insulated Torque Wrench when:

Fastening is performed on electrical systems up to 1,000 volts
Electrical insulation is required during fastening
Proper torque is critical to the electrical connection
Over-torque conditions need to be controlled
An adjustable torque wrench is preferred
Different torque settings are required within the wrench's range
A square-drive wrench is appropriate for the application
Battery terminals or other electrical connections require controlled torque

Mountz specifically designed these wrenches for high- and low-voltage electrical assembly applications where torque control and operator safety are important.

When Should You NOT Use This?

The Insulated Torque Wrench may not be the best choice when:

Torque requirements fall outside 40–180 lbf.in (4–20 N·m)
A preset production wrench is required
Operators should not be able to change the torque setting
A cam-over or break-over mechanism is preferred
Electronic torque measurement or fastening data collection is required
Torque-angle measurement is required
The tool's insulation is damaged or compromised

The wrench's voltage rating does not replace appropriate electrical safety procedures, training, PPE, or applicable workplace requirements.

How the Insulated Torque Wrench Works

The wrench combines an adjustable click torque mechanism with insulated construction.

During operation:

The operator selects the required torque setting.
The appropriate socket is installed on the square drive.
The wrench is positioned on the fastener.
Torque is applied slowly and smoothly.
When the selected torque is reached, the wrench clicks.
The operator stops applying force after the click.

The insulated construction helps reduce the possibility of shorting or shock when the tool is used within its intended electrical application. Mountz's operating instructions specify double insulation with red inner and yellow outer layers and PVC heat-shrink insulation.

Result:

Controlled torque for electrical fasteners
Reduced risk of over-tightening
Clear torque indication
Electrical insulation for applicable fastening environments
Improved process control for critical electrical connections

Core Features

Adjustable insulated click torque wrench
Designed for electrical systems up to 1,000 volts
Nonconductive insulation
Double-insulated construction
Red inner and yellow outer insulation layers
PVC heat-shrink insulation
Adjustable torque setting
Square drive design
Audible and tactile click torque indication
Helps reduce the possibility of shorting or shock
Suitable for applications such as battery terminal fastening
Two drive-size options
ISO 6789:2017 accuracy and repeatability requirements at ±4% of setting

The Mountz data sheet describes the tools as adjustable square-drive torque wrenches designed to provide torque control while helping prevent shorting, arcing, and other electrical damage. The operating instructions provide the additional double-insulation construction details.

Available Models

The current Insulated Torque Wrench lineup includes two models with the same torque range but different square drive sizes.

Insulated Torque Wrench Model Chart

Model	Item #	American Torque Range	S.I. Torque Range	Drive Size	Length	Weight
SLO1/4I	060398	40–180 lbf.in	4–20 N·m	1/4" Sq. Dr.	8 5/8"	1.3 lbs
SLO3/8I	060113	40–180 lbf.in	4–20 N·m	3/8" Sq. Dr.	8 5/8"	1.3 lbs

Model Selection Guide

If you need:	Recommended Model
40–180 lbf.in with 1/4" drive	SLO1/4I
40–180 lbf.in with 3/8" drive	SLO3/8I
Smaller square drive configuration	SLO1/4I
Larger square drive configuration	SLO3/8I

Because both models have the same torque range, selection primarily depends on the square drive size required for the application and socket configuration.

Insulation & Electrical Protection

The defining feature of these torque wrenches is their insulated construction.

Mountz's SLO operating instructions specify:

Use on electrical systems up to 1,000 volts
PVC heat-shrink insulation
Double insulation
Red inner insulation layer
Yellow outer insulation layer
Reduced possibility of shorting or shock
Suitability for applying torque to battery terminals

The contrasting insulation layers also provide a practical visual indicator. If the outer insulation becomes damaged enough to expose the inner layer, the tool should be removed from service and evaluated before further use.

Setting the Torque

The Insulated Torque Wrench is adjustable, allowing the operator to select the required torque within its 40–180 lbf.in (4–20 N·m) range.

General setup:

Determine the torque specification for the fastener.
Adjust the wrench to the required torque value.
Install the appropriate socket onto the square drive.
Confirm that the insulation is clean and undamaged.
Position the wrench securely on the fastener.
Apply force slowly and smoothly.
Stop applying force when the wrench clicks.
Follow your facility's procedures for storing or resetting the wrench after use.

Calibration & Accuracy

Mountz specifies the Insulated Torque Wrenches as designed and manufactured to meet or exceed the accuracy and repeatability requirements of ISO 6789:2017 at ±4% of setting.

For calibration, Mountz recommends using a torque tester or torque sensor that covers the wrench's range.

For click wrenches:

Use a compatible torque tester or sensor.
Connect the wrench using the appropriate adapter.
Use First Peak mode when testing with a digital analyzer or transducer.
Apply torque clockwise slowly and smoothly at the load point near the end of the handle.
Allow the wrench to click and note the reading.
Adjust as required.
Repeat testing to verify the setting.

Standards & Compliance

The Insulated Torque Wrenches are designed around both torque accuracy and electrical fastening requirements.

The product data sheet specifies:

ISO 6789:2017
±4% of setting
Protection for applications up to 1,000 volts

The data sheet also states that the wrenches meet IEC6900 Standards.

Common Applications

Mountz Insulated Torque Wrenches can be used for:

Battery terminal fastening
Electrical equipment assembly
Electrical panel assembly
Power distribution equipment
Electrically live fastening applications within the tool's rating
Industrial electrical maintenance
Battery-powered equipment
Electrical connection assembly
Applications requiring controlled torque and insulated tooling

Mountz specifically notes battery terminal fastening as an application in the SLO operating instructions.

Use Cases (Real-World Examples)

Battery Terminal Fastening

Problem: Battery terminals require controlled torque, while conductive tooling can introduce electrical hazards.

Solution: The Insulated Torque Wrench combines adjustable torque control with insulated construction for fastening battery terminals within the tool's intended electrical rating.

Electrical Equipment Assembly

Problem: Electrical connections must be tightened to specification while minimizing the possibility of shorting or arcing.

Solution: The wrench provides controlled torque and nonconductive insulation to support electrical fastening applications.

Multiple Torque Requirements

Problem: An electrical assembly contains fasteners requiring different torque settings.

Solution: The adjustable design allows the operator to select different values within the 40–180 lbf.in range using the same wrench.

Socket Compatibility

Problem: Two applications require the same torque range but use different socket drive configurations.

Solution: Select the SLO1/4I for a 1/4" square drive or the SLO3/8I for a 3/8" square drive.

Maintenance

Inspect the wrench and insulation before each use.
Keep the insulated surfaces clean and free from contamination.
Check for cuts, cracks, punctures, abrasions, or other insulation damage.
Remove the tool from service if the insulation is damaged or compromised.
Inspect the square drive and torque mechanism for wear or damage.
Periodically verify torque output using a calibrated torque analyzer.
Recalibrate according to your facility's calibration schedule and applicable quality requirements.
Store the wrench in a way that protects the insulation from physical damage.
Avoid exposing the insulated surfaces to conditions that could degrade the insulation.

Integration & Advanced Notes

Mechanical adjustable click torque wrench
Requires no electrical power
Designed for electrical systems up to 1,000 volts
Double-insulated construction
Adjustable 40–180 lbf.in torque range
Available with 1/4" or 3/8" square drive
Both models have the same torque range, length, and weight
Audible click indicates when selected torque is reached
Compatible with torque analyzers for calibration and verification
Designed for electrical assembly where both torque control and insulated tooling are required
No electronic data collection or torque traceability

Media & Supporting Content

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