<HTML> <TT>I promised to describe the tool used at Hubbard Harpsichord used to make consistent balance rail mortises in keys.</TT><TT></TT> <TT>The tool is chucked into a drill press and used on pre-drilled keyplanks (in this case the center rail is drilled at the same time to assure spacing); however, the same tool could be used for individual keys or just for key button mouldings.</TT><TT></TT> <TT>The working end has parallel sides corresponding to the width of the desired mortise, also matching the hole drilled in the work. The profile, looking at one of the flat sides, is tapered according to the depth and length of the desired mortise, with a larger taper at the end (for keys so the base of the mortise flares at the balance pin hole). The tapered sides are filed into v-notches and honed so that a cutting edge is formed where they meet the parallel sides.</TT><TT></TT> <TT>The tool should be made of hardenable steel, either cylindrical or a shape that can be chucked, with a diameter that is at least as large as the necessary length of the mortise. Drill rod should come with instructions for hardening, but it is fairly easy to do with a propane torch and water (heat the sharp edges to a _straw color_, quench, then draw the hardness by heating to red..). Additionally, a chisel corresponding with the width of the mortise (or smaller) should be made or obtained to clean out the waste and ragged edges.</TT><TT></TT> <TT>I'll post the results.</TT><TT></TT> <TT>Clark</TT></HTML>