I am trying to do some aluminum engraving so I need some help and advice. I want to make some engravings on a small bunch of extruded black aluminum case. The only engraving tools that are at my disposal are 0.0mm, 0.2mm, and o.5mm v-groove carbide. I do not need a deep engraving since my cases are black hence my Doc is just 0.1mm. During my first try, I used a 0.5mm cutter spindle at maximum (24k), feed300mm/min, Doc 0.1mm. the tip got snapped just as a little passed halfway. I tried the 0.2mm cutters with the speed rate back to 150mm/min. 90% of the work was completed before the tip got damaged. I got tired of snapping the tips so i tried the shape point V-groove cutter. The work was finished without any damage on the tip but the cut and the finish is bad news.. Where could i have gone wrong? Any help and advice please?