Bad tapper

[RogerP]

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.

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

BugBear

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

 

[MikeK]

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

 

[Eric The Viking]

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...

 

[Beau]

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...

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.

 

[J-G]

No-one has mentioned progressive taps.

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?
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...

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

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.

 

[Eric The Viking]

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).

 

[J-G]

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.

 

[Beau]

Thanks for the explantion J-G

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

 

[MusicMan]

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.

 

[hawkeyefxr]

+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

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.

 

[MikeK]

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.