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lent guidelines to help you choose the spe-cific type of Steel you should use for the part you are making. Now, you need to select the actual piece of Steel stock you will shape. Steel is commercially available in round rods, fiat sheets and other shapes such as sąuares, rectangles, octagons, etc. Choose the shape and size of the Steel stock so it is just large enough to cut out the part. The closer the piece of steel is to the finał dimensions of the part, the less work you will have to do! For example, the Remington Model 12 firing pin we will make to illustrate this chapter will be cut from a piece of steel stock three eighths inch (%” =.375”) wide by three sixteenths inch (-Yie” = .187”) thick, by two and three quarters inch (2%”) long. The finished dimensions of the firing pin are approximately .320” wide by .134” thick by 2.130” long. So, we only need to remove about .055” from the width, .053” from the thickness and about .620” from the length. It simply makes good sense to pick a piece of steel that lets you lay out the part with the greatest ease. Since the bottom of our Remington Model 12 firing pin is straight, we’ve selected a piece of steel stock that has one, nice, straight edge so we can match the straight edge of the steel stock with the straight bottom of our firing pin, and save consider-able work and time. Finally, we left a little extra length to use as a “handle” to hołd the steel stock in a vise, making working on the part easier and preventing accidental dam-age to the part itself.

LAYOUT OF THE PART

First, thoroughly clean the Steel with a good solvent to remove all traces of oil or grease. Next, coat at least one side of the steel with Dykem or a similar layout fluid to provide a blue or black coating which can be easily scribed or marked. If you try to layout the part without using Dykem, you can have the devil’s own time spotting your layout lines! Your scribe will easily scratch through the layout fluid and leave a nice, sharp, silver linę that is easy to see.

To lay out the Remington Model 12 firing pin, begin by scribing the center linę for the cutout in the middle of the part. This center linę is .156” from the bottom of the firing pin. The piece of steel we chose has a straight edge which we will use as the bottom of the firing pin, making it easy to locate this center linę. Now locate where the initial holes need to be drilled, and center punch their locations (see Figurę 3).

FIGURĘ 3 - The original steel blank (top), trimmed slightly. Below is the blank with the initial center linę scribed through the Dykem coating.

Before doing any drilling, finish the layout of the entire firing pin, making a very accurate drawing of the firing pin on the Dykemed surface (see Figurę 4). If you make a mistake, it is very easy to correct by

FIGURĘ 4 - Lay out the part complctely before doing any cutting.

applying a bit morę Dykem and redoing that part of the layout. The morę precise the layout, the morę accurate the part will be. Try to use a single point as your initial reference or “index point” for all or as many measurements as possible. If you measure from point “A to point B”, “B to C”, and “C