Using a tool for angular torque measurement, like an angular torque gauge often paired with a breaker bar or torque wrench, involves measuring rotation after an initial torque has been applied to a fastener.
Based on the provided reference, here's how you use an angular torque gauge to apply torque accurately by angle:
Steps for Using an Angular Torque Gauge
An angular torque gauge is a simple tool that measures the degree of rotation applied to a fastener. It typically attaches to a socket and sits between the socket and the wrench or breaker bar.
- Connect the Tool: Insert your breaker bar (or torque wrench) into the designated slot at the top of the angular torque gauge. The gauge itself will be placed over the fastener's socket.
- Position the Gauge: Ensure the gauge is properly aligned and the pointer or needle is set to zero or the starting point, often achieved by rotating the gauge body while holding the center hub or pointer stationary.
- Apply Torque: Begin to tighten the fastener using the breaker bar or wrench.
- Monitor the Angle: As you tighten, watch the needle on the gauge. It indicates the number of degrees the fastener is rotating from its starting position.
- Reach Desired Setting: Continue tightening the fastener until the needle reaches the specific angle required for your application (the "desired setting").
- Completion: Once the needle reaches the target angle, you have applied the correct rotational measurement.
By following these steps, you ensure that the accurate tension, specified by the angular requirement, is applied to your job. This method is commonly used for critical fasteners, like cylinder head bolts, where yield is involved and torque-to-yield specifications are necessary.
Why Use Angular Torque?
Applying torque by angle is often more accurate than just using a torque specification alone, especially for critical fasteners. It accounts for variations in thread friction and ensures a consistent clamping force by rotating the bolt a specific number of degrees past a initial torque value, bringing the bolt into its elastic or even plastic deformation range.
