The humble hand file has been the tool of choice for smoothing, honing, cleaning and deburring various materials since the Stone Age.
Today, hand files are now generally made from high carbon steel and come in many shapes and sizes, making them fit for a multitude of purposes.
A file has the following main parts:
- Tang- A plastic or wooden handle is fitted on the file’s tang. Some files have built-in handles moulded over the tang. Others, like a farmer’s file, have wide, flat tangs that serve as handles.
- Heel or shoulder - The part that does not have teeth is called a heel or shoulder, and serves as the base of the file.
- Belly or Face – this is where all the “filing” happens. Some files have more than two bellies or faces, and can feature different tooth patterns on each.
- Cutting Edges - Teeth are cut on its face and edge so that it can perform the job of cutting
- Tip or Point - the end you point at the work.
The features of a hand file are:
Length A file’s length is measured from the base of its heel to the end of its point. The tang or handle is not included when determining the length.
Shape or kind - a file’s name is usually derived from its cross-sectional shape, eg square, flat, triangular, half round and round.
Grade or cut - files are graded according to the size and spacing of cutting teeth.
Most hand files are classified as Swiss Pattern or American Pattern.
American Pattern files are available in three grades of cut: Bastard, Second Cut and Smooth.
The three standard cuts in regular use:
- Bastard - is a course file for roughing down work to a general shape where a good finish is not required
- Second cut - used on hard metals, across narrow surfaces (more teeth in contact with the work), or for general work to close sizes requiring a reasonable finish
- Smooth - produces a very fine finish.
The length of a file affects the coarseness, regardless of the cut. For example a 6″ Bastard Cut is a lot finer than a 12″ Bastard Cut. This is because shorter files are generally used for finer work. Overall, the finest would be a 4″ Smooth file and the coarsest would be a 16″ Bastard file.
On the other hand, Swiss Pattern files, are available in seven cuts, ranging in coarseness from ØØ to the finest cut of No. 6. Made to exacting measurements, these files are smaller and finer than American Pattern files, and are ideal for detailed work, such as work by jewelers, watchmakers, model makers, and tool and die makers.
Single cut files (top) have one set of teeth. Double cut files have two (bottom).
Applications of Hand Files
- sharpening tools
- cleaning relay contacts
- cleaning painted or rusted surfaces for earthing purposes.
Half round file
- produce both flat and concave surfaces
- cleaning large steel conduits internally
- enlarging cable entry into cubicles etc.
- for opening up holes and finishing concave surfaces
- filing mounting holes for meters, lamps or switches in component case
- enlarging entries into motor connections boxes, switchboards, mounting blocks etc.
- slotting mounting holes.
- for making square and rectangular holes
- filing mounting holes for switches in component case
- filing keyways in pulleys, etc
- filing mounting holes for coach bolts.
- clearing out square corners and filing acute internal angles greater than 60 degrees
- re-shaping damaged threads on bolts and screws, etc.
Filing at its best is an art form. There are three main filing techniques.
- Straight filing is pushing the file lengthwise down the object in a straight or slightly diagonal position. The cutting stroke is the push stroke. Done correctly, the return stroke shouldn’t touch the object. Straight filing can deliver maximum material removal or smooth final finish
- Draw filing involves holding the file at both the tang and the point, and pulling it across the object towards you. Like straight filing, draw filing can provide maximum material removal or a smooth finish.
- Lathe filing is the process of stroking the file against an object that is revolving in a lathe. This can be useful when either truing an object or for removing material.
Filing Different Metals
Because different metals vary greatly in properties, consider the nature of the metal you’re working with when choosing the right file for the job. Soft, ductile metals require a keen edge and light pressure. Harder materials require duller teeth and more pressure.
- Filing Stainless
Tough, dense and abrasive, stainless steel requires a file with good wearing qualities. Apply light pressure and a slow, steady stroke.
- Filing Aluminum
Soft and difficult to file, aluminum easily clogs. Use an aluminum file, with a special cutting edge that breaks up the filings, prevents over filing, and helps reduce chattering. Apply a shearing stroke to the left for the best finish.
- Filing Brass
Brass is difficult because it’s softer than steel, but tougher and harder than aluminum. Filing brass requires a sharp file with sturdy teeth and a cut that prevents grooving and running. Use a specifically designed brass file, and apply moderate pressure.
- Filing Lead
Please wear a Respirator! Soft materials such as lead and copper present distinct filing conditions. Use a short, single cut file with stubby teeth. Apply normal pressure.
- Filing Bronze
Similar to brass but dependent on the content of alloying elements. Cross the direction of the cutting stroke to avoid grooving.
- Filing Wrought Iron
Wrought iron is soft and ductile and does not require a very sharp file for good results.
- Filing Plastic
Hard plastic requires a file with high, sharp teeth. Soft plastics are filed in shreds, so a shear tooth file should be used in this application, as well as in other soft materials like aluminium, copper, hard rubber and wood.
Taking Care of Hand Files
- Keep files clean and dry. Get a file card or brush and get into a habit of using it after each job. A file card has rows of small, stiff wire that cleans debris from a file’s teeth. Remember that filing creates heat and filings are sharp. Cleaning your file by hand is one way to enter a world of pain!
- Never rap a file on a solid surface or strike it with a metal object.
- Never subject the file to bending or excessive pressure. Apply only enough pressure to allow the file to do the work.
- Store files separately from each other and from other tools. Protect the teeth. Tossing your files in with all your metal tools is not a good idea! Ideally, hang them up or keep them in a drawer with non-metallic dividers and enough room to fit without a lot of contact. Store them away from water, dirt, grease and filings.
- Check that the handle is not split and that it fits securely.
Now you ready to create a smooth masterpiece! For the best files, look no further than Tools for Schools.