Even if you got it too hot, that would only make it softer. Won't cut as well if it's softer, but it would be less likely to break than an undamaged tap.

I'm assuming this is a farily large tap (for the head bolt holes perhaps ) and it takes a good amount of force to break a tap that large. Just be careful and take your time - and don't force anything. 1/8 - 1/4 turn in, 3/4 turn back to clear the chips. When bottoming a hole, go until you think it is done, then clean the hole out and try again.

 

I was taught about 30 years ago that when regrinding a tap it should never be heated to the temperature point where you can not hold onto it with your bare hands. It was grind, quench in coolant, then grind etc...otherwise the tempering changes and the tap can snap off.

 

Got the truck back and I'm ready to clean out the threads in the block. Should I be able to run the tap in the block with only my fingers? I can only get it to thread in about 1 or 2 threads/turns?? I didn't want to use a wrench/force until I know the correct way. I don't want to start making new threads etc. Any suggestions? Thanks alot.

 

Find a nut that fits the old head bolts and run the tap through that. Then run the stud into that nut and see how it feels.

 

As Long as the tap was not discolored after you chopped it, you are fine. I use Kroil as the coolant on all my tapping, as well as center fire rifle cleaning, etc. It is wonderful stuff. Ya can't get too much in the hole, either! Pour it on!

 

Ok next and hopefully the last question, can I go to a part store such as NAPA and buy a tap wrench? Or what is the best thing to turn this tap?

 

That or a 3/8 square drive socket will do the job. I like a standard tap handle myself, the short bar keeps me from putting too much force into it.