I cut one down and I drilled through a Swiss Army flint to to put on my key chain. (Lots of sparks) I used a air cut off wheel and a air drill. Put them on concrete of the driveway with a water hose just in case, but no fires. Magnesium won't catch on fire when cut in big chunks and water is useless to put it out, it's the shavings you worry about. In big chunks it is fine and works great, you could do it with a hacksaw but the harbor freight $9 air cut off wheel works great on a lot of stuff.