File (tool)

File (tool)

A file is a tool used to remove fine amounts of material from a workpiece. It is common in woodworking, metalworking, and other similar trade and hobby tasks. Most are hand tools, made of a case-hardened steel bar of rectangular, square, triangular, or round cross-section, with one or more surfaces cut with sharp, generally parallel teeth. A narrow, pointed tang is common at one end, to which a handle may be fitted.

Types of Files

Files come in a wide variety of shapes, sizes, and coarseness levels, designed for specific tasks. The most common types include:

• Flat File: Rectangular in cross-section and used for general purpose filing where a smooth finish is not required.
• Round File: Circular in cross-section and used for enlarging round holes or smoothing curved surfaces.
• Square File: Square in cross-section, used for filing square holes.
• Triangular File: Three-sided in cross-section, often used for filing the angles of a workpiece or sharpening the teeth of a saw.
• Half-round File: A file with one flat and one curved surface, ideal for smoothing both flat and curved surfaces.

File Coarseness

The coarseness of a file indicates the spacing of the teeth and is related to the finish the file will leave on the workpiece. The common grades of coarseness from roughest to smoothest are:

• Coarse: Rapid material removal with a rough finish.
• Bastard: A medium grade for moderate material removal and finishing.
• Second Cut: Finer than bastard for lighter material removal and smoother finish.
• Smooth: For fine finishing work.

Usage

Files are used by applying them to the workpiece with forward pressure on the push stroke. The file is lifted away from the workpiece on the return stroke to prevent dulling the teeth. The selection of file type and coarseness depends on the material being filed and the desired finish.

Care and Maintenance

To maintain the effectiveness of a file, it should be cleaned regularly with a file card or brush to remove trapped chips. Files should be stored in such a way that their teeth do not touch each other or other hard surfaces, to prevent them from becoming dull.

History

The development of the file dates back several centuries, with significant advancements made during the Industrial Revolution. Files were once made by hand, but most are now manufactured using precision machinery, ensuring consistent quality and performance.

See Also

• Rasp
• Abrasive
• Metalworking
• Woodworking