I like Chuck's idea of using a wood vee block and wood drift, but I think I would rather apply the force in a more controlled manner with a small arbor press. Same thing could be done horizontally in a vise. I have seen case hardened guards and some guards are somewhat brittle. Look at how many actually do break, especially across the tang screw hole where there is less strength. So a little heat would not hurt. Even temps lower than those which will produce temper colors will make steel less brittle. The steel mill where I worked in the 1970's would soak 20 ton coils in a large tank of near boiling water before slitting certain high carbon/high alloy stuff in order to keep the narrow strips of scrap from constantly breaking while being wound up in the scrap baler. This was especially helpful in the winter when the steel was ice cold. We made a lot of steel that was used for grenades and cluster bombs that would often shatter like glass even when it was still glowing coming off the Hot Mill.
