Turn down shaft of tap

With the interupted cuts and what I have to work with, I would chuck the tap in a drill and head over to the bench grinder. Dont over heat it. Don't take off any more metal than you have to, and dont leave a sharp transition up to the original diameter or that is the spot it will break. The other option is a tool post grinder.
 
use a hand drill in a vise and use your angle grinder. easy and take your time not to heat it up.
Dave
 

Machining an HSS tap should not present a major problem. I quite like hard turning, even on my little benchtop lathe.
 
buy a different tap. a) that one is a basic hand tap and you'll have more success with a spiral point (through hole) or spiral flute (blind hole) tap b) thinning the shank weakens the tap which may = broken tap. Presumably the pros have thought about this and accounted for it in their deep hole/ reduced shank taps. Taps are cheap, getting one out of the last hole in a piece you spent hours working on is not :)
 
mattthemuppet2 said:
Taps are cheap, getting one out of the last hole in a piece you spent hours working on is not :)
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I try to teach my guys , if you're gonna F it up , do it in the beginning of the job . That way you don't waste much time . :rolleyes:

Back to the point though , they sell the relieved taps or mount in a whirly jig and grind them on a surface grinder .
 
Try not to use carbide on an interrupted cut, especially on harder material. Grinding is the 2nd best solution. Buying the correct tap is the best.
 
All i can think of is that if in a similar situation, i would likely need the tap right away so ordering a pulley tap wouldn’t be an option i would want. Any of these expeditious means would be cool. Hard turning is really a fantastic thing but not something i have learned enough about to get consistent results. your guys photos and advice are registering with me. Thanks.
 
I have a number of taps in my favorite sizes that I ground down the shafts on for deep hole clearance. Don't make this any harder than it has to be. Three minutes with a bench grinder and you're done.
 
macardoso said:
I too have done as you described. A wider included angle insert will be stronger for example a square insert with a 90 degree corner will be stronger than the 50 degree included angle on your DCMT insert.

I recommend NOT reducing the shank smaller than the tap drill. The tap can cut crooked more easily if the shank is reduced too small.
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I see IRWIN brand on the tap shank.

That must be a carbon steel tap (not HSS).
 
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