🔍 Key Concepts

• Lathe tool hand (right-cut vs left-cut) – look at which direction the cutting edge faces relative to the workpiece rotation and tool travel. • Tool purpose by shape – compare tool S’s point and flank shape with the clearly threaded tool in the figure and with broader ‘roughing’ tools. • Side-facing vs turning – notice whether tool S is arranged to cut along the side (face) of a shoulder or along the length of the shaft.

💭 Think About

• Look closely at tool S’s cutting edge and chip flow direction: if the carriage moves from right to left, which way would S remove metal? • Compare tool S with the obvious threading tool in the illustration: does S have the sharp, V-shaped point for cutting threads, or a broader edge for general metal removal? • Ask yourself whether S is aligned more to work on the shaft’s diameter or on the shoulder face; that will tell you if it is primarily for side-facing.

✅ Before You Answer

• Verify which end of the lathe is the headstock and which way the work is turning, then determine whether S cuts on a right-hand or left-hand pass. • Confirm whether the tool tip on S is a V-shaped threading form or a more blunt cutting edge suited for roughing. • Check if S is positioned to machine a shoulder face or the cylindrical surface; that distinction separates a side-facing tool from a plain roughing tool.