I've made my own similar to those you can buy and I've also modified Stanley and Wera screwdrivers to fit correctly with diamond files or slow wet grinding so there's no need to anneal then re-harden and temper. I've found the old pre WW2 to 1960's Stanleys to be probably the best (toughest) steel around, some of the modern stuff even from quality manufacturers doesn't hold a candle to the old steels. Some people say it's because of various bombs going off that contaminated post war steels however I just think the post 1960 steels are usually inferior possibly because of other contaminants in recycled steels. I'm not a metallurgist I just know enough to get by to heat treat carbon and alloy steels without destroying them. Wera seem to be around the best of the modern steels for screwdriver and hex bit manufacture.