Hand filing — during which stroke is metal removed? When using a hand file correctly with forward pressure on the work, during which part of the stroke is the significant cutting action achieved?

Introduction / Context:
Hand filing is a basic bench skill. Understanding when the teeth engage and remove material leads to better finish, longer tool life, and reduced operator fatigue. Applying pressure at the wrong time dulls the file and produces chatter marks.

Given Data / Assumptions:

• Standard single- or double-cut file with handle.
• Proper technique: apply pressure on the push (forward) stroke; relieve pressure on the pull (return) stroke.
• Workpiece is securely clamped in a vise.

Concept / Approach:
File teeth are oriented to cut on the forward stroke. Pressing during the return stroke causes rubbing rather than cutting, loading the teeth with swarf and rapidly dulling edges. Smooth, long forward strokes maximize contact and help maintain flatness; the file is lifted slightly or pressure is eased on the return to avoid back-cutting.

Step-by-Step Solution:

Verification / Alternative check:
Manufacturing handbooks and training manuals specify “cut on the forward stroke” as standard practice; files are produced with rake suited to this direction.

Why Other Options Are Wrong:

• Return or both strokes: would cause excessive wear and poor finish.
• “None”: contradicts the very function of a file.
• Impact at ends: filing is not an impact process; controlled sliding is required.

Common Pitfalls:
Applying pressure both ways; using too short strokes; not cleaning file with a card, leading to pinning and scratches.

Final Answer: