Originally Posted by
Salamandrine
While you can make a quick and dirty tap this way, for something like this IMO it is important to have some extra length to keep the alignment straight all the way through. Why take a chance on a crooked pedal? Plus it's a highly stressed interface. It might be fine to retap a kids bike or something, but I would splurge on the real tool if retapping a high quality crank like an old TA or Stronglight.
FWIW I like the Hozan taps because they have an extension piece to make sure they cut straight. They are still available and cost ~ $30.
I also have the Hozan taps for this reason but I haven't found a tap handle that fits them. They are also slightly larger than a pedal thread at the fat end so you have to stop about halfway down the tap lest you cut your pedal hole bigger than it ought to be.