Power tapping tap holders

[mklotz]

There's another good reason for drilling all the way through with the tap drill. If the hole the tap drill is intersecting is small, the tapered tip of the tap may not be able to make full threads to the intersection before bottoming out on the opposite side of the hole. A through hole provides a place for the tapered tip to go. A bottoming tap might solve the problem but keeping a full selection of tap types can get expensive.