I’ve made a few of my own tools over the years and it gets to be a pain to have to make a new handle each time, especially if the tool doesn’t work out too well. I have made a few collet handles but I’ve also made a few of these. The one on the left is for a guy at my club, it’s made of alloy and bored 1/2”. The smaller one on the right is for me and made from stainless steel bored to take 1/4” tools. The lower parts have been sand blasted to aid gluing. Both will in due course be epoxied into Ash handles.