I had to tap a new 8mm thread, as the old 6mm had stripped completely
so I got the hole to about 6.2mm and started to tap the thread, it was a bit tight, and the tap broke, no warning or creaking,
So, what could I do, as the part is not really replaceable under the current guidelines,
it was sheared in the hole, so nothing to grip, small tweezer type plyers just bent,
I was getting really annoyed,
In the end, I got three nails, just normal wood nails, and forced them into the three cut outs in the tap, and after a couple of goes with plyers,
managed to unscrew and free the tap, and out it came along with the nails that all looked like a spring, but they did the job!!
How would anyone else tackle a broken sunken tap ??
Steve
Personally I would have drilled the hole the right size, the only time I have ever broken a tap was using it in the tailstock of my lathe and feeding
it too fast, 6.2mm is miles to small, you were basically asking the tap to gouge out at least .5mm of material+ cutting the thread, how did I get it
out I unscrewed it with a pair of long nosed pliers.
Shooter
6.8mm is m8 tap size
You invented your own tap remover! Also available commercially - these work quite well
https://www.ebay.co.uk/i/173541711340?chn=ps&var=472227225204&norover=1&mkevt=1&mkrid=710-134428-41853-0&mkcid=2&itemid=472227
225204_173541711340&targetid=878706529565&device=c&mktype=pla&googleloc=9044936&campaignid=9794911188&mkgroupid=101625062844&a
mp;rlsatarget=pla-878706529565&abcId=1139126&merchantid=114916188&gclid=EAIaIQobChMI7N3b2vW76QIV1vhRCh2iYgSYEAQYAiABEgKstvD_BwE
I know that my 6.2 mm was too small. but the nearest I had was 7mm and that also would not of work of worked
any way, its sorted now
steve
Broken taps are a bugger for sure, but you seem to have it sorted.
Broken bolts still take some persuasion and I usually find a left hand drill bit followed by some concentration a punch and a small hammer help me
(not always though).
Anyway glad you have it out and are able to move on - I hope you can rescue what remains of the hole/thread!
I was making a cylinder for a 5" gauge steam locomotive, and one of the last jobs was to tap the many small holes in the cast iron (probably a
1/8" tap). And, you guessed it, I broke the tap on one of the very last holes. This was a casting that I'd spent upwards of 50 hours
machining.
I ended up taking it to a local machine shop and they got it out with a spark eroder, under a "do it when you've got a spare moment"
arrangement. Got a call back the next day: the tap was out and the hole was still in good shape. Cost me £5 in the beer fund, IIRC.
So, the moral of the story is - if you can take the part to a machine shop you'll save a lot of grief and may not cost as much as you think.
quote:
Originally posted by nick205
Broken bolts still take some persuasion and I usually find a left hand drill bit followed by some concentration a punch and a small hammer help me (not always though).
Wish I knew of a local machine shop that would do stuff for beer tokens and was actually competent. All the ones I know of only take on jobs £100+
when they're totally slack - most of the time it's "not worth their time". Hence I now have most of the tools I need to be self
sufficient.
That includes a full set of metric tap drills and taps - these things always go wrong!
Usually you can get the broken tap out with a centre punch and a hammer.
[Edited on 18/5/20 by coyoteboy]
quote:
Originally posted by coyoteboy
Wish I knew of a local machine shop that would do stuff for beer tokens and was actually competent. All the ones I know of only take on jobs £100+ when they're totally slack - most of the time it's "not worth their time". Hence I now have most of the tools I need to be self sufficient.
That includes a full set of metric tap drills and taps - these things always go wrong!
Usually you can get the broken tap out with a centre punch and a hammer.
[Edited on 18/5/20 by coyoteboy]
I get that it's not really worth their while, and I know they need to make cash, not friends, but it does work both ways.
Worth their weight in gold if you find one.
quote:
Originally posted by David Jenkins
I was making a cylinder for a 5" gauge steam locomotive, and one of the last jobs was to tap the many small holes in the cast iron (probably a 1/8" tap). And, you guessed it, I broke the tap on one of the very last holes. This was a casting that I'd spent upwards of 50 hours machining.
I ended up taking it to a local machine shop and they got it out with a spark eroder, under a "do it when you've got a spare moment" arrangement. Got a call back the next day: the tap was out and the hole was still in good shape. Cost me £5 in the beer fund, IIRC.
So, the moral of the story is - if you can take the part to a machine shop you'll save a lot of grief and may not cost as much as you think.