Tap and die recommendations

[chipmunk]

Thanks guys, those are the tap sizes for conventional taps, as given for example in the Zeus book. I know those well.

I was perhaps not clear enough - the issue is that for serial taps the first tap is only very slightly larger than the conventional tapping drill size and so often doesn't really engage well and cut a decent thread. I think that the serial tap drill sizes are probably less than these by some margin - say diameter minus 1.5 x threadpitches?

Jon

 

[jasonB]

Serial taps use the same size tapping drill as normal ones which can usually be worked out for Metric by subtracting the pitch from th emajor diameter.

Where you do use a smaller tapping drill is when using thread forming taps which may be what you are thinking of. These have little or no flutes so don't cut away any metal, instead what they displace from the crest fills the root. As an example the M6x1.0 needs a 5.5mm tapping hole rather than 5.0mm for a conventional tap

J

 

[The Bear]

Hi

Its been a while since I started this thread but I've now bought the individual taps I need. On the basis of the advice here I scouted around for ages and got what I needed in Dormer E500 very cheap.

I have a couple more questions. Since I've got good quality do I need a good quality tap wrench or will any cheapo do. Are they much the same or are named ones better for some reason? Suggestions please.

Also do I need to buy a couple of different sized wrenches? Biggest tap I have is M12, smallest M4. I see wrenches that will hold both, but if I buy only one is it likely to be too unwieldily on the 4s or too small on the 12s?

Thanks in advance

Mark

 

[shipbadger]

Mark,

Yes you will need some different sized tap holders. Although you may find one covering the whole range it will be far too clumsy for M4 if it will cope with M12, and you stand a good chance of breaking the tap. I would suggest that you will need two, more likely three. Tapping by hand needs some practice, if you know how to do it OK, but if not come back to this thread and I or someone else will explain. Essentially you need to develop a feel for what is happening and a too large holder will prevent this. With regard to make, as with all tools cheaper ones will have less effort put into their manufacture. They will do the job but common faults include adjuster screws that are sloppy or taps that are not held at a right angle to the handle. I've all sorts from real cheapies to decent ones made by Eclipse. As you've managed to source some decent taps it woould be a shame to spoil the job for a happence of tar.

Tony Comber

 

[Spindle]

Hi

As said above, you will need different sized wrenches and I'd go for good quality if only for the in hand feel. For the smaller sizes I find the 'T' bar type wrench easier to handle, standard type for larger sizes, (above M6).

Regards Mick

 

[The Bear]

Thanks guys
Whats a good make for tap wrenches, without breaking the bank, esp if a need a couple or three

Mark

 

[Hemsby]

Hi

The best & probably the cheapest is not to buy hand taps.

Buy Spiral point machine taps you only need one tap per thread size, as the name suggests they are made for machine tapping but can easily be used conventionally by hand.

They are produced with a very short slight taper and require a degree of “lining up by eye when starting the thread if using by hand from then on its no problem. You can always start the thread in a bench drill to ensure a vertical start by rotating the tap in the drill chuck by hand for the first few threads.

The advantage of machine taps is that they are designed to cut continuously without having to stop, until you reach the required depth

For thru holes no problem, if you are tapping a blind hole and need to get closer to the bottom you can always grind some of the point off.

Spiral point designed to push the swarf forward so perfect for thru holes and where there is a small clearance at the bottom of the drilled hole

Spiral flute taps are for tapping blind holes and are designed to bring the swarf up out of the hole. These taps are weaker than spiral point due to their design

It is probably 40 years + since I used hand taps only ever bought spiral point or spiral flute taps for my engineering factory mostly used on machines but also use many times for hand tapping. Retired now and have a small selection of spirals still and occasionally have to buy a new tap but would only consider spiral point taps

This link is just one I came across http://www.parkertools.co.uk/Product/04 ... iral+Point

I would only consider HSS

 

[The Bear]

Hemsby
Thanks for the reply. As per my previous posts I have already bought the taps, luckily for the set of 3 HSS Dormers I spent less than your link for one. Appreciate your suggestion may be quicker but thats not really going to be a problem for the level of use they'll get.
However you seem to know what your taking about, so do you have a suggestion on a make for the tap wrench?

Cheers

Mark

 

[Hemsby]

Hemsby
Thanks for the reply. As per my previous posts I have already bought the taps, luckily for the set of 3 HSS Dormers I spent less than your link for one. Appreciate your suggestion may be quicker but thats not really going to be a problem for the level of use they'll get.
However you seem to know what your taking about, so do you have a suggestion on a make for the tap wrench?

Cheers

Mark

Hi Mark

Sorry that will teach me to read things better.

Although you have already bought your taps if you need to buy more in future, might be worth trying a spiral point, because they normally have only 2 flutes (3 on hand taps) and they cut like a hot knife thru butter even in the hardest of steels.

I would not worry about the price you pay for a tap wrench its really not important for occasional use they all do pretty much the same job, main difference is a straight or "T" type and that is what feels most comfortable in your hands .

The cheaper wrenches have a fixed V in which the top of the tap fits and the rotating section of the wrench handle secures against the opposite side of the tap.

The better quality have the fixed V but the rotating section of the wrench pushes an opposite sliding V trapping the square of the tap. (hope this makes sense could not think how to explain this)

"T" wrenches have a square collet clamping arrangement

Die holder choice can be a bit more tricky. In some of the cheaper versions the bore in the holder that holds the split die can be too big and there is a danger that if you apply too much pressure on the screw that forces the die open it can split the die in two

Good Luck =D>

regards

Keith

 

[Spindle]

Whats a good make for tap wrenches, without breaking the bank,

Hi

Look out for Moore and Wright, Presto or Eclipse - all good makes that will last several lifetimes.

If you have the time and inclination, boot sales are a pretty good source and electrolysis will remove any corrosion

Regards Mick

 

[The Bear]

Thanks guys

Mark