That is all there is too it. The total time to produce the set screw after a junk box screw of the proper size has been found is well under 3 minutes. Now that sure is a lot better and cheaper then a trip to the hardware store. Lastly, do not forget to have in place the proper safety measures such as safety glasses, and if possible, return the unused portion of the junk box screw to the junk box, you never know when you will need it again. I have found that the longer I have had a junk box item, the sooner I will need it when I toss it out.
Skip the text below if you are not interested in how a machine screw gets its size.
Machine screws are normally described in terms of 0-80, 2-56, 3-48, 4-40, 5-40, 6-32, 8-32, 10-32, 10-24, etc. up to size 16. The first number, by way of a formula is the diameter and the second number is the number of threads per inch. There is usually a coarse thread and a fine thread that can be found for each size. A fine thread is preferred in thin materials or when greater strength is desired.
The machine screw numbering system follows closely to a logarithmic scale where an increase in a screw number size will approximately double the tensile strength of the screw. This screw number is found by the formula d = (# x .013) + .060, where "d" is the nominal diameter.
Using this formula, a #10 screw has a diameter of .190" (or 3/16" in practical terms), a #5 screw has a diameter of .125" (1/8"), and so on. The formula applies only for screw thread numbers that are #0 and higher, but does NOT apply to smaller Unified miniature screw thread series. Typically screws smaller than size #0 are supplied in the Unified Miniature Series. The formula for number sizes smaller than size #0 is, d = .060" - (#zerosize x .013) with the zero size being the number of zeros after the first. So a #00 screw would be .047" in diameter, #000 would be .034" in diameter and so on.
Time for a history lesson,
The number series of machine screws at one time included odd numbers such as 9, 11, 13, and so on and even extended up to #16 or more. But standardization efforts some time in the late 19th and early part of the 20th century reduced the range of these sizes considerably. Now, it is much less common to find machine screws larger than #14, or odd number sizes other than numbers, #1, #3 and #5. Even though it is possible to find screw sizes #14 and #16, they are not nearly as common as sizes #0 through #12.
Sizes starting at a 1/4" diameter and larger are designated as 1/4"-20, 1/4"-28, and so on. In these examples, the first number is giving the diameter in inches and the second number is the number of threads per inch. Most thread sizes can be found in UNC or UC which stands for Unified Coarse Thread, or UNF or UF which stands for Unified Fine Thread.