Special tools can be made out of necessity.;) IE finding a way to tap a hole out that is in a corner where the tap wrench will not turn a full revolution freely.:eek:
Take a 6/32 steel self locking nut, with the soft jaws of your vise, press the inverted nut on the square end of the 6/32 tap. Now you can use your 1/4 drive long extension and a 6/32 socket to tap the hole out to 6/32. The same is true for 8/32 10/32 1/4 5/16 3/8 both fine thread and course thead. In general what ever tap size you want to tap; that same nut can be pressed on to the tap. If not, mic the square end of the tap, and drill out the nut a fraction smaller, or slightly grind off just two sides of the square end of the tap and press it on the nut. I bought a new tap set and made a complete set of "Corner Taps" this way.:D