Working principle of manual torque wrenches

A Manual Torque Wrench is a hand tool used to apply a specific amount of torque to a fastener,

such as a bolt or nut. It operates based on the principle of leverage and mechanical deformation.

1.Handle: The wrench consists of a handle that provides the user with a grip for applying force.

2.Torque adjustment mechanism: Manual torque wrenches have an adjustable mechanism near the handle

that allows users to set the desired torque value. This mechanism can vary depending on the design 

and brand of the wrench but typically involves rotating or sliding scales, 

indicating the torque in units like foot-pounds (ft-lbs) or Newton-meters (Nm).

3.Spring and click mechanism: Inside the head of the Torque Wrench, there is a spring-loaded 

lever called a clicker or click mechanism. This component is responsible for triggering an

audible "click" sound when the preset torque value is reached during tightening.

4.Ratcheting system: The head of most manual torque wrenches incorporates a ratcheting 

system that allows for both clockwise and counterclockwise 

rotation while maintaining tension on the fastener during operation.

5.Application process: To use a manual torque wrench, you typically follow these steps:

- Set the desired torque value by adjusting the scale near the handle.

- Attach an appropriate socket or bit to match your fastener.

- Apply force to turn or tighten your fastener using smooth, steady movements.

- As you approach your preset torque value, you will feel increased resistance in turning.

- Once you reach this point, continue applying force until 

you hear/feel an audible "click" from the click mechanism inside the head.

- At this moment, stop applying further force as it

indicates that you have achieved your desired torque level.

It's important to note that manual torque wrenches require periodic calibration to ensure

their accuracy since factors like wear and tear can affect their Performance over time.

Manufacturers often provide guidelines for calibration intervals and procedures specific to their products.