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Question

Difficulty: MediumChisels, Files, and Planes

When using a standard hand file to deburr and shape the edge of a metal workpiece clamped in a vise, what is the correct stroke technique to ensure efficient cutting and prevent premature tool wear?

  1. A
    Apply firm, continuous downward pressure during both the forward push stroke and the backward return stroke
  2. Apply downward cutting pressure only on the forward push stroke, and relieve pressure or lift the tool slightly on the return strokeAnswer
  3. C
    Apply heavy cutting pressure exclusively on the backward pull stroke while lifting the file completely on the forward stroke
  4. D
    Move the file in a rapid back-and-forth scrubbing motion with continuous downward pressure to maximize friction

Answer

Apply downward cutting pressure only on the forward push stroke, and relieve pressure or lift the tool slightly on the return stroke.
Standard machinist hand files are manufactured with teeth that slant forward, away from the handle. As a result, the tool only cuts metal on the forward push stroke. Relieving downward pressure or lifting the file slightly on the return stroke prevents the delicate cutting edges from dragging backward against the hard workpiece, significantly extending tool life and maintaining cutting efficiency.

Step-by-Step Solution

1
Analyze the directional cutting orientation of standard hand file teeth
Hand file teeth are manufactured with a forward slant (rake angle), designed to shear material exclusively when pushed forward away from the handle
Understanding the tooth geometry identifies that cutting only occurs on the push stroke
2
Determine the proper motion and pressure regulation on the return stroke
Downward pressure must be relieved or the file lifted slightly above the workpiece surface during the return stroke
Dragging teeth backward against the metal workpiece under downward load generates excessive friction and breaks or rounds over the microscopic cutting edges

Key Concept

Directional Cutting Action and Stroke Technique of Hand Files
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Topics

Chisels, Files, and Planes

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