I must admit I was a bit mystified about handles. There is probably some longstanding methods known 100 years ago that has lost its way in modern times. I'm still mystified. Some woodies I bought had a teeny pilot hole, nothing else. Is it like the Japanese knife blade, heat up the tang & burn it in? I just assumed drill them out & use my finest epoxy. Removing them is a tomorrow problem LOL. Then I got some woodies with a steel threaded insert. Fit some tangs, not others. Some refused to thread even though the size felt right. Hmmm.. there are different sizes to these then. But darned if I could find a diagram or table based on file length or whatever, they vary like crazy. When I bought a few files from Gesswein I tried a few of their (same brand) handles. They are plastic but have the threaded insert & they really bite the tang. They dohave a cross reference table (to their files) but I've used them on other files just by trial & error. They are every comfortable to the hand.