1. Defining the Flat File: The technical description provided in the question specifically defines the
Flat file. This is a general-purpose tool characterized by the following:
• Cross-Sectional Shape: It has a rectangular cross-section, meaning it is wider than it is thick.
• Tapering Geometry: Unlike some other files, the flat file is
tapered in both width and thickness towards its point (the tip). Typically, the first two-thirds of its length from the heel are parallel, while the final third tapers to allow the tool to enter smaller gaps.
• Teeth Arrangement: The broad flat surfaces (the faces) have double-cut teeth for efficient material removal, while the narrow sides (the edges) have single-cut teeth.
2. Distinction from the Hand File: This is the most common area of confusion. While both are rectangular:
• The
Hand file is parallel in width for its entire length (it does not taper in width).
• One edge of a hand file is typically a "safe edge" with no teeth, allowing the user to file one surface without damaging an adjacent vertical wall.
3. Summary of Use: Because of its dual-tapered shape, the Flat file is highly versatile for smoothing large flat surfaces and working in corners where a fully parallel file might be too bulky to maneuver.