🔍 Key Concepts

• Lathe threading tool orientation relative to the workpiece axis • Difference between thread-cutting tools and facing/turning/parting tools in the illustration • How the cutting edge of a threading tool must match the thread form and angle

💭 Think About

• Look closely at each labeled tool in the figure: which ones have a V-shaped form that could match an external or internal screw thread? • For each answer pair (e.g., L/P, L/U), ask yourself: do BOTH letters point to tools that are clearly arranged for cutting threads rather than just turning or facing? • Consider the direction of feed: which tool positions would allow the tool to track along the workpiece and generate a helical groove rather than just remove material from the end or diameter?

✅ Before You Answer

• Verify which letters in the illustration correspond to V‑shaped tools aligned parallel to the workpiece axis, suitable for following the thread pitch. • Make sure the selected figures show the tool set so its point is centered on the workpiece and the flanks of the tool would form the thread sides, not a flat or radiused surface. • Before choosing, eliminate any figures where the tool clearly looks like a facing or parting tool (cutting straight across the face) or a broad-nose turning tool (large flat cutting edge), since these are not threading tools.