Thread: Tapping square holes, or, tapping holes square?

Th,

Here's another bit of handiness - https://www.woodworkforums.com/showth...27#post1552027

My problem with tapping on/in the mill is running out of Z. I've used a variation of your pointed guide for tap alignment when using my drill press which is simply a piece of brass rod turned to match the across the flats dimension of my smaller Goliath taps. They don't have centre holes. That third hand would come in real handy at times.

BT

Of the dozens of taps I have , I think about two have centering holes. I have three different size chuck type tap holders; fortunately, they all have centering holes. I must say though, I haven’t had a case where I’ve run out of travel though, you must tap some very deep holes.

248mm of Z runs out real quick.

Quill travel and Z clearance are 2 very different things.....

I have to say why bother with the whole tape center, be it plain or sprung. Just stick the tap in the chuck, turn the machine on and then off and drive the tap in while the machine is coasting. The tap will start straight and true every time.

Ew

Originally Posted by Anorak Bob

248mm of Z runs out real quick.

Not as fast as 160mm of Y when you use the horizontal spindle to do some line boring..... PDW

Originally Posted by Ueee

Quill travel and Z clearance are 2 very different things.....

I have to say why bother with the whole tape center, be it plain or sprung. Just stick the tap in the chuck, turn the machine on and then off and drive the tap in while the machine is coasting. The tap will start straight and true every time.

Ew

OK, you've started the hole nice and true. Then what Ew? In my case, turn the motor back on and snap the tap. If I was in that much of a hurry I'd use my tapping chuck but then I'd have to buy some spiral taps and so it goes on........... The Z comment was based on the inability more often than not to even fit the tap and the handle between the spindle nose and the workpiece on the mill. The drill is a different thing altogether, adequate quill travel, copious Z.

BT

Sorry, i just sort of stopped there with the tap stuck in the chuck and the job

Undo the chuck, now you can finish by hand. Mind you i have only done this with gun and spiral taps and my hole is normally about 75-80% contact. To this day i have not broken a HSS tap, the only tap i think i have ever broken was an M5 carbon steel tap.

Ew

Hi Bob,
If the tap goes into the drill chuck and not overly tightened it can slip before it breaks.
Raise the quill and finish the hole with the tap wrench.

Phil

I didn't mention it Phil, but as taps have hard shanks (unlike drill bits) they do not hold very well in drill chuck and will spin before anything else happens

Ew

Small taps of five six milimetres you can break using two fingers, stick them in a drill and you lose all feel and it's very difficult to see what's happening at 60rpm. I hate trying to get broken taps out, but not as much as throwing out an almost finished project because you can't get the broken bit out - prefer to take my time...

Originally Posted by Ueee

Quill travel and Z clearance are 2 very different things.....

I have to say why bother with the whole tape center, be it plain or sprung. Just stick the tap in the chuck, turn the machine on and then off and drive the tap in while the machine is coasting. The tap will start straight and true every time.

Ew

Yep ! That works for me ! I've run 8BA taps into brass this way. Touch wood, not broken one....... Yet
When the drill stops, drop the tap out and finish with a wrench.

Originally Posted by th62

Small taps of five six milimetres you can break using two fingers

What nonsense, there is no way you could break a tap like tha.......

Of course, how silly of me, your using taps made in Asia from recycled washing machines. But then your not making rockets are you?

Ew

About 90% of the taps I have I bought when I was living in Malaysia, they're all Asian, the remainder I've bought in Australia, never checked where they are made. Interestingly I still have just about all of the taps, except for the two and three mm taps which I manage to break every now and again, and the five and six mm taps of which I've only broken a couple.

I think about the the only people that couldn't break a five or six mm tap, even 'quality' branded, would have to have something wrong with their fingers/wrists.

I started this thread because I thought it might be of interest or helpful to someone, so far at least one has. That aside, if you don't find it interesting or helpful, stick to your far superior tools and methodology and report this post to the moderators - I'm sure they'd be only too happy to remove it on your behalf.

This thread started out quite civil, don't understand why you would want to change that...

Viva la ferramenta C#!ne$e...

Unfortunately it's all too easy to break a small tap with two fingers, and it doesn't matter what brand it is.
I think old mate was talking about breaking the tap using only a finger on each end of the tap wrench, not breaking it like a match stick.

I thought it was a good idea to post the suggested technique, it's one I've used for years and will continue to do so.
It works for taps that are too big for your chuck and it also works for starting reamers.
Cheers,
Greg.