We have two types of file handles: Wire-bound and Skroo-Zon.

Here at the shop, we mostly use the wire-bound type. For these types of handles, you simply insert the tang of the file into the end and either rap the butt of the handle onto your bench top, or hold the handle in one hand and rap the end of the handle with a hammer. I mostly use the latter method.

The Skroo-Zon handles are internally threaded. The file is literally screwed into the handle. These are great handles. I use this type with the 4 xx-slim files simply because the handle is smaller in diameter and it encourages me to use a light hold on the handle and light pressure when filing.