Intro to Millwright Practice Exam

What action should be taken periodically when tapping to prevent the tap from binding?

1. Turn the tap continuously

2. Reverse the tap one-quarter turn

3. Apply more force

4. Lubricate the tap

The correct answer is: Reverse the tap one-quarter turn

When tapping, it is essential to periodically reverse the tap one-quarter turn to prevent it from binding in the material. This backward motion helps to break any chips or debris that may have accumulated in the threads of the tap, reducing the friction that can cause binding or galling. As the tap cuts into the material, it generates swarf (the chips produced during cutting) that can clog up the tap's flutes. By reversing slightly, you create space for these chips to escape, allowing the cutting action to continue smoothly. In addition to helping avoid binding, this technique also reduces the risk of damaging the tap or the workpiece, which could occur if excessive force is applied. Properly using a tapping technique that includes this periodic reversal maintains the effectiveness of the tap and ensures cleaner, more accurate threads.