Every gunsmith needs a selection of files and the ability to use them. The first you can buy, the second you must learn.
   Files have continuous rows of teeth that extend across their faces at an angle. Files with rows of teeth oriented in one direction are called mill files. Files with rows oriented in both directions are called double-cut or flat files. Mill files generally provide smoother finishes than double-cut files and are more useful for gun work. The closer the rows are to each other, the finer the cut of the file in use.
   Coarse files are called bastard files. Medium files are called second-cut files. Fine files are called smooth files. Quality files are expensive, so you will have to build your collection over time. For starting out, you will probably want at least one 8" mill file in smooth cut and another, perhaps 10", in second-cut. A few more basic files you probably need include a round and a half-round in 8" smooth. You’ll also want a 6" or 8" triangular file.
   For working on dovetails you will need a special file designed for that work. This file has parallel rather than tapered sides, but only one side has cutting teeth. The other two sides are “safe,” which means they do not have teeth.
   If you are doing much stock work, you will need to add a few wood rasps, which are closely related to files. The teeth are different, and they do not serve the same purpose. Get at least one each in flat, round and half round.
   Also consider a couple of Stanley Surform tools, which are like rasps. These are fast-cutting wood removal tools with replaceable blades. They are inexpensive and are handy for stock work when you need to remove a lot of material in a single pass.
You will also need a set of small “needle” files, which are used in tight or small locations and for delicate work. Guns are full of tight and small locations, so they will see a lot of use. As you progress with your gun work, you will discover that you need many more sizes, shapes and cuts of files, but these will get you started.
   Always use an appropriate file handle whenever you use any file. File handles lessen hand and arm fatigue and give you more control of the file for more consistent, even cutting strokes, which will improve the appearance, accuracy and final result of your work. There is a safety issue as well. The tapered end of a file is made to fit in a handle, but it can puncture your hand in a heartbeat.

A full range of files includes needle files for jobs such as finishing sight dovetails [lead photo]. Storing files in a case [2] spares them from damage. Chalk rubbed into a file’s teeth [3] prevents the buildup of metal fragments. Both coarse and fine files [4] are necessary in specific applications. A file card’s stiff wire bristles remove built-up material from between rows of teeth. [5] Stanley Surform tools quickly remove wood from stocks. [bottom photo]

   To use a file, hold the handle in one hand and grasp the front of the file with the other hand. This allows more control over the pressure, direction and angle of the cut. Check after every couple of strokes to make sure you are cutting what you want to cut and where you want to cut it.
   Before use, rub file chalk into the teeth. The chalk collects between the teeth and helps prevent metal chips from sticking and building up on the file. This is known as “pinning.” Pinning inhibits the cutting effectiveness of the file and can score or scratch the surface of whatever you are working on.
   Never pull a file backward across the workpiece, unless you want a useless and dull file. Push forward to cut, and then lift the file clear of the workpiece on the return stroke. Files cut on the forward stroke only. Maintaining pressure and pulling the files backwards will roll the sharp edges of the file teeth and dull the file. Also be careful about what material you use a file on, as filing hardened or plated metal can quickly dull your files.
   A file card is a stiff, wire brush specially made to clean filing residue from between the file teeth. Use the file card frequently while working to keep the file teeth clean and clear of chips.
   Files should be stored so they never contact or touch one another. Files are very hard and very brittle. Contact between files can lead to chipped, broken or damaged teeth.
   Do not dump files together in a toolbox or drawer, as that can dull or damage them. (I will plead guilty to this and speak from experience.) Wrap them in a shop rag to protect them and always protect a file from rusting.
   Given proper care, files will last for many years and provide excellent service. I have some that I have owned since the 1970s, and they are still working fine. I have a few others that my wife’s grandfather gave me that I suspect are older than I am. He was a tool and die maker so they saw a lot of use before I got them. They are worn and showing their age, but they are still working.
   Any time you are cutting or filing anything on a gun, remember you can always remove material. But, replacing material after you mess up and remove something you did not intend to remove is extremely difficult—and often impossible. Always pay attention, work slowly and look more often than you file.
   Check your work from several angles. When viewing your work from one angle as you file away, you often you think you are doing a great job, but when you view your work from another angle, it becomes obvious that the file is cutting more in one location than another. The tendency is to file in something other than a square, flat plane.