# Bad tapper



## DigitalM (19 Nov 2017)

I'm a craptastic tapper. In attempting to tap a 6mm thick mild steel disc with a 1/4" 20G tap, i was, I reckon, about 5 degree out. It works, but meh! - you'd frown if I handed you the result.

Now, I realise that I run the risk of one-liner answers like "practice" (do it anyway, I know, it's that obvious) but I'm only ever going to need to do metalwork projects once in a blue moon, as it will be those jobs that are in support of my woodworking stuff. So, I won't be getting much practice.

Sooooooo - I see a few people using drill presses on you tube with dead centres. I looked a little more into this and in the US you can get spring loaded dead centres for just this sort of thing. Well maybe there's something in that but you can't get them here.

I guess putting a set square up against the job is a no-brainer.

But in my position, total noob, not much kit apart from my NOS Draper (Japan!) 1980s metal boxed tap and die kit, are there any simple/cheap ways to ensure being closer to true square?


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## marcros (19 Nov 2017)

http://www.warco.co.uk/tap-die/303208-t ... hment.html

I can't help on the other- I tend to use my lathe for alignment if I can


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## RogerP (19 Nov 2017)

Put the tap in the pillar drill chuck and turn by hand into the work-piece. It will do if you can only get a couple of turns to get it started. Then take the tap out of the drill chuck (but not out of he work-piece) and finish off with a tap handle


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## DigitalM (19 Nov 2017)

Thanks for both of these guys, much appreciated.


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## sunnybob (19 Nov 2017)

You can leave the tap in the pillar drill chuck if you want, depends on your hand strength whether you can do that or not.
Just remember to back out a half turn after every forward turn to clear the swarf out on the first run through.


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## t8hants (19 Nov 2017)

Another trick is to take an off-cut of wood, cut a V notch in it ensure the faces of the V are square to the sides of the timber.
Now put your tap into its hole and bring the jig up to it until it holds the tap square in the V and then clamp the jig.
The timber needs to be thick enough to support the tap until it is well into the hole and the thread has started square to the face.
Or try and stand directly over the work piece and look down straight onto the top of the tap, as most taps have a little countersunk hole in the top, make sure it remains static and does not describe a circle as you turn the tap.


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## NazNomad (19 Nov 2017)

RogerP":rty3mmk7 said:


> Put the tap in the pillar drill chuck and turn by hand into the work-piece. It will do if you can only get a couple of turns to get it started. Then take the tap out of the drill chuck (but not out of he work-piece) and finish off with a tap handle



Exactly what Roger said. You know for sure it's gone in upright then.


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## Eric The Viking (19 Nov 2017)

I take the belts off the press and use the quill pulley as a handwheel. This has the big advantage I can use the quill drive hand levers to put some weight behind the tap for the first few turns. I have also found that putting a slight countersink on the edge of the hole, and cutting compound, both really help starting.

But, generally speaking, the bigger the thread, the more I hate the task.


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## bugbear (19 Nov 2017)

I find taps are OK - it's dies that cause me a LOT of trouble.

BugBear


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## hawkeyefxr (19 Nov 2017)

Yep lathe or pillar drill for alignment only then tap by hand, and don't buy rubbish taps, by that i mean cheap ones. They will get very sticky as you tap and usually snap just as you get to the bottom. 
A lot of dies are die nuts, that is there is no adjustment for them they just cut the thread, In doing so they are removing a lot of metal and you get tearing and part of the thread get ripped away. Use split ones and screw the small screw in on the stock for the first pass, then gradually release the adjusting screw on the following passes with the die.
I had some cheapo taps and dies and suffered as you seem to be, i then purchased one tap it's drill size the cost was the same as the entire cheapo set, but i could tap a 4mm hole in stainless no trouble as all.
Also use a good cutting agent, i recommend Rocol, quite expensive but it will last you years you just need a pin head of Rocol tapping liquid is all.
One other thing get yourself a Zeus book, it gives you all the drill sizes for tapped threads you will ver need. The first one i bought on the 60s was 50p, ten bob then and dammed expensive for an apprentice. If you have trouble find it let me know i scanned mine in so i do not lose it.


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## Beau (19 Nov 2017)

I am not great with the tap holder but find it much easier just using a gutsy cordless drill. So quick to reverse and clear and easy to hold square IME. Sure all the proper metalworkers will throw their hands up in horra but works for me. The drill press idea sounds good though for precision


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## NazNomad (19 Nov 2017)

If you do enough of it, there's always a tap guide...







Not worth the layout for 1 or 2 threads a year though.


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## DTR (19 Nov 2017)

^^^^ or just drill some appropriate holes in a handy bit of scrap. 

I've got one of those sprung loaded centres but I rarely use it; I usually find I haven't got enough headroom, or there's a clamp or something in the way of the tap handle. I usually tap using the drill chuck as mentioned above, or I use this contraption:


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## MusicMan (19 Nov 2017)

+1 to using a pillar drill, V notch in wood, tap guide, cutting fluid, reversing tap every turn (actually I usually do it every half turn; turn it as far as I can on one hold, reverse till I feel the waste metal being cut off, then change hand position and repeat).

That little indent that t8hants mentioned is accurately centred. As you say, you can use a spring loaded centre in that with a drill press (you can get them here as wood lathe drive centres, just ignore the jagged bits). But you can do it without a posh centre, a plain dead centre or even a rod filed down to a point in the drill will do. Clamp the work down with the hole centred (best way is to do this right after drilling with it clamped). Put the tap in the drill and start the thread as described above. When you need the extra force of the tap wrench, loosen the chuck and replace it with the centre and put the wrench on the tap. Push the tap down with the quill, and lock it if the quill locks. Then do a turn, backing off then turning till it engages. Push the quill down a bit then repeat.

Admittedly this is easier if you have three hands, but it is only a bit slow if you use the centre to realign the tap after every turn, and for a few threads a year this is worthwhile.

No-one has mentioned progressive taps. These come in sets of three; the first two are both tapered and have a smaller diameter than the final size. I find these really useful for something very tough, like stainless steel. Unfortunately you can't always tell from an advert if they are progressive!

Keith


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## DigitalM (19 Nov 2017)

DTR":e9gz8cgu said:


> ^^^^ or just drill some appropriate holes in a handy bit of scrap.
> 
> I've got one of those sprung loaded centres but I rarely use it; I usually find I haven't got enough headroom, or there's a clamp or something in the way of the tap handle. I usually tap using the drill chuck as mentioned above, or I use this contraption:



Not seeing the contraption, could you possibly repost.


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## DigitalM (19 Nov 2017)

NazNomad":335fwlqo said:


> If you do enough of it, there's always a tap guide...
> 
> 
> 
> ...



Yeah that looks awesome, but like you say £20+


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## RogerP (19 Nov 2017)

bugbear":qd1426j4 said:


> I find taps are OK - it's dies that cause me a LOT of trouble.
> 
> BugBear


One of the first things I made on my metal lathe was a Tailstock Die Holder. Since then it's been so easy to get perfect threads.


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## DTR (19 Nov 2017)

DigitalM":34anrdv8 said:


> DTR":34anrdv8 said:
> 
> 
> > ^^^^ or just drill some appropriate holes in a handy bit of scrap.
> ...



Hmm, I thought it was just banjaxed at my end. Let's try that again...






Made from a drill stand picked up at the bootsale, with some modification


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## bugbear (19 Nov 2017)

RogerP":1avwozeq said:


> bugbear":1avwozeq said:
> 
> 
> > I find taps are OK - it's dies that cause me a LOT of trouble.
> ...


A metal lathe is an expensive pre-requisite for simple threading!

BugBear


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## DTR (19 Nov 2017)

bugbear":1xtqw6n8 said:


> RogerP":1xtqw6n8 said:
> 
> 
> > bugbear":1xtqw6n8 said:
> ...



No reason you couldn't do the same on a wood lathe


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## RogerP (19 Nov 2017)

bugbear":22rnmmef said:


> RogerP":22rnmmef said:
> 
> 
> > bugbear":22rnmmef said:
> ...


Indeed it would be if that's all one bought the lathe for!


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## MikeK (19 Nov 2017)

This is the tap attachment that came with my Wabeco drill stand. The largest tap I have is the M10, and this works well.


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## Eric The Viking (20 Nov 2017)

MusicMan":19rdvrpp said:


> No-one has mentioned progressive taps. These come in sets of three; the first two are both tapered and have a smaller diameter than the final size. I find these really useful for something very tough, like stainless steel. Unfortunately you can't always tell from an advert if they are progressive!


Hi Keith,

Sorry to display my ignorance, but are these different from the taper + 2nd + bottoming sets I have? If I am doing through holes, I always start with the taper and run the second through afterwards to clean the thread. Is there a better alternative?

Every cheap boxed set I have seen from the sheds only seems to have seconds (rather than all three), and it is getting quite hard to find the three together from my local tool shops - some staff look at you as if you're speaking Greek.

The ones you describe sound like two undersize and a finishing tap - have I got that right? If so, I assume they are not used in a normal production environment, as you wouldn't want to run two taps through the same hole, but they ought to give a really good finish by hand...


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## Beau (20 Nov 2017)

Eric The Viking":69r5ealn said:


> MusicMan":69r5ealn said:
> 
> 
> > No-one has mentioned progressive taps. These come in sets of three; the first two are both tapered and have a smaller diameter than the final size. I find these really useful for something very tough, like stainless steel. Unfortunately you can't always tell from an advert if they are progressive!
> ...



I my have got the wrong end the stick but this is the only set I have and they come in sets of three https://www.tilgear.info/kal032tds--kal ... 0and%20die

I also have a longer tap that you can get through in one but I mainly use that on aly.


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## J-G (20 Nov 2017)

Beau":1p8s76wx said:


> Eric The Viking":1p8s76wx said:
> 
> 
> > MusicMan":1p8s76wx said:
> ...


There is no indication that the taps in that set are 'progressive' - or what you really mean 'Serial' as described by ArcEuro. I don't know of any other supplier of these 'Serial' taps which are quite different from the traditional 1st, Second & Plug in that besides having a longer or shorter taper lead, the OD is also reduced on the 1st and 2nd, only the last or 'plug' tap being full size/form. 
See this page on ArcEuro's site:
http://www.arceurotrade.co.uk/Catalogue ... ric-Coarse
_(I have no connection other than being a satisfied customer)_

The fact that the linked to set also has 'solid' dies rather than 'split' would also indicate that the taps are more likely to be standard Taper, Second & Plug.


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## Eric The Viking (20 Nov 2017)

Thanks for that J-G: the ones from ArcEuroTrade don't look expensive either, and would be a lot nicer in things like cast iron (in which I have a fair bit to do soon).


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## J-G (20 Nov 2017)

Eric The Viking":1kwd8aqr said:


> Thanks for that J-G: the ones from ArcEuroTrade don't look expensive either, and would be a lot nicer in things like cast iron (in which I have a fair bit to do soon).


You're welcome - when I was doing my apprenticeship I often remarked to my mentors that I couldn't understand why the 1st and 2nd taps were also 'full form' after the taper, so when I saw ArcEuro were offering these 'Serial' Taps I made a mental note and as-and-when I need to replace taps I buy these.


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## Beau (20 Nov 2017)

Thanks for the explantion J-G 

I did say I might have the wrong end of the stick


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## MusicMan (20 Nov 2017)

Looks like you've got it sorted now. The Kilgear set you show looks the same as mine (different brand) and these are progressive/serial even though it doesn't say so.

6 mm is a good size to start practising. pipper and it is hard work, smaller and the tap breaks too easily.


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## hawkeyefxr (20 Nov 2017)

MusicMan":31ng7dvm said:


> +1 to using a pillar drill, V notch in wood, tap guide, cutting fluid, reversing tap every turn (actually I usually do it every half turn; turn it as far as I can on one hold, reverse till I feel the waste metal being cut off, then change hand position and repeat).
> 
> That little indent that t8hants mentioned is accurately centred. As you say, you can use a spring loaded centre in that with a drill press (you can get them here as wood lathe drive centres, just ignore the jagged bits). But you can do it without a posh centre, a plain dead centre or even a rod filed down to a point in the drill will do. Clamp the work down with the hole centred (best way is to do this right after drilling with it clamped). Put the tap in the drill and start the thread as described above. When you need the extra force of the tap wrench, loosen the chuck and replace it with the centre and put the wrench on the tap. Push the tap down with the quill, and lock it if the quill locks. Then do a turn, backing off then turning till it engages. Push the quill down a bit then repeat.
> 
> ...




The sets of three are taper, second and plug. from my experience if you buy just the one tap it will most likely be a second. If you go to en engineering type place they will ask what you want.


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## MikeK (20 Nov 2017)

This must be yet another difference between UK and US terminology. In the US, single-thread tap sets come as a set of three taps: taper, plug, and bottom. The taper tap is used to start the threads in a through hole, and if the tap can continue through the material past the first nine or ten threads, then nothing more is needed. If the hole to be threaded is a blind hole or a through hole with obstructions, then either the taper or plug tap is used to start the thread and the bottom tap is used to get as close to the bottom of the hole as possible.


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