Awesome info and advice Odin. I've never seen thread chasers like that before. I need a set. I'm adding those to my Christmas list right now .

I've always just made do with regular taps but you are absolutely correct about the difficulty in starting them without cross threading and the potential damage that may cause. Yes bottom taps help a lot but I would never be able to find a 12 x 1.25 bottom tap locally.

Another tip I've learned that hard way. Using a tap or thread chaser in a drill might seem like it's a good idea but trust me, it's not.