Oh NO!!! Broken Tap!

MrWhoopee

MrWhoopee

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Jan 20, 2018
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I was tapping a bunch of blind 10-32 holes in some hardened material. Not Rc 60 hard, but Rc 40-45 anyway. I was being very careful, lots of Tap Magic, lots of forward and back, lots of sweat. Suddenly, TINK! NOOOOOO........!!!!! There were some shards of the tap sticking up, but of course they broke off. I then went after it with punch and hammer, hoping to break it up. No joy. I let it sit overnight while I contemplated my situation. Today I decided to try making a spade drill from the shank of a broken 1/4" carbide endmill. First I started rough grinding it on the SC wheel on my bench grinder. Then I decided to get smart. I chucked it in my cordless drill et voilá, crude centerless grinder. I didn't put a lot of effort into the point, just a simple chisel edge, raggedy and off-center. It took multiple attempts and trips back to the grinder, chipping the end then running out of clearance as the "drill" got shorter and the hole got deeper. Rather than use the quill, I fed up with the knee for better control. Ultimately I prevailed, all of the tap removed with minimal damage to the threads.

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Man, you were lucky!!!!!! Just had the same experience in a piece of 1018 and the broken tap is still there. Had to move the hole over and start again. Good Job!!
 
MrWhoopee said:
Rather than use the quill, I fed up with the knee for better control.
Click to expand...
The quote above struck me......
With my huge ancient mill I have no "quill" and therefore no quill feed......what's worse is that the knee is likely several hundred pounds.....so, no feedback there......what machine are you using?

Brian
 
brino said:
The quote above struck me......
With my huge ancient mill I have no "quill" and therefore no quill feed......what's worse is that the knee is likely several hundred pounds.....so, no feedback there......what machine are you using?

Brian
Click to expand...
Kent, BP clone. For something like this it's more about listening than feeling.
 
brino said:
The quote above struck me......
With my huge ancient mill I have no "quill" and therefore no quill feed......what's worse is that the knee is likely several hundred pounds.....so, no feedback there......what machine are you using?

Brian
Click to expand...
Kent, BP clone. For something like this it's more about listening than feeling.
 
MrWhoopee said:
Yeah, never had any luck with those, I've bent and broken the fingers on a couple. Sort of like EZ outs, if it works, it wasn't really stuck.
Click to expand...
Most times that I have taps break, they shatter in the hole, if so the tap extractor will not work, as the shattered pieces wedge together preventing rotation, if the tap breaks off without shattering, one has a chance to remove it, otherwise I take a punch that will fit into the flutes and drive out the chips and with another larger punch I try to break up the tap into small pieces that can then be picked out, it is never fun! Now one of our SVHSM group has an EDM machine that we may make use of, I have not needed it yet ---
 
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