AWS Welding Inspection and Testing Certification Practice Test

To test a grinding stone for cracks, what is the recommended action?

1. Visual inspection only

2. Tap the stone in four places and listen for a ring

3. Soak the stone in water

4. Use a hammer to strike it

The correct answer is: Tap the stone in four places and listen for a ring

The recommended action for testing a grinding stone for cracks is to tap the stone in four places and listen for a ring. This method is effective because it relies on the principle of sound. A grinding stone that has structural integrity will produce a clear, ringing sound when tapped. In contrast, a stone with cracks or defects will emit a dull or muted sound, indicating compromised quality. This approach allows an inspector to detect internal flaws without causing damage to the stone. It is a widely accepted technique in the industry for ensuring the safety and effectiveness of grinding stones during use, helping prevent accidents or tool failure that could arise from using a defective stone. The other options, such as visual inspection only, may miss internal cracks that are not readily visible on the surface, while soaking the stone in water does not assess structural integrity and does not provide any useful information about cracks. Using a hammer to strike the stone could potentially cause additional damage and is not a standardized method for testing. Hence, tapping the stone and listening for a ring remains the most reliable technique for this purpose.