Question 60 QMED05 - Machinist-Pump Technician

The Correct Answer is D **Explanation for D (mark on metal):** The metal scribe (often a hardened steel pin or needle) housed in a combination square's head is a precision marking tool. Its primary and intended purpose is to score or mark precise lines onto surfaces, specifically metal, wood, or plastic, where a pencil mark would be too thick or easily erased. This ensures accurate layout and cutting. **Why the other options are incorrect:** * **A) clean file teeth:** While the scribe is sharp and hard, it is not designed for cleaning files. Specialized tools like a file card or wire brush are used for removing swarf (material fragments) from file teeth. Using the scribe risks damaging the file's teeth or the scribe itself. * **B) punch gasket holes:** The scribe is a delicate marking instrument and lacks the structural strength or the correct tip shape needed to punch holes in materials like gaskets. This task requires a specialized punch tool. Using the scribe this way would likely break or dull the tip immediately. * **C) remove packing:** "Packing" (such as gland packing or similar materials used in mechanical seals) is typically removed using dedicated hooks or scrapers designed to withstand prying and pulling forces. The scribe's sharp, thin point is inappropriate and too fragile for the heavy-duty task of removing lodged packing material.