Cutting wire is a challenge and if it is hard, it is extra difficult. If it is hard wire in a confined space, extra extra difficult. Fortunately dentists have overcome this issue with long reach and weird shaped tools. One that is on general sale are Tungsten Carbide tipped cutters ($10). They make short work of any narrow diameter wire that I have come across. They cost not much more than standard cheap electronics wire cutters, but with the advantage of not being blunted by anything harder than copper. I fiddle and DIY and occasionally make jewellery. I am faced with these challenges of hard to reach harder wires. These things are the answer, even the cheap ones.
-- Max Leadley-Brown
Hard Wire Cutter ($10)
Available from Amazon