Taps & dies

Mr Grumpy

Mr Grumpy

Western Thunderer
hi,
I'm hoping to expand on my tools and would like to purchase some taps & dies.
Please can anyone pass on some info as to the most apropiate sizes to buy?
Either BA or metric?
I noticed boxed sets vary in price from around £150 to £250, so I want to be sure to get it right!!
Thanks,
Richard
 
Mike W

Mike W

Western Thunderer
I find personally than even sizes of BA do almost everything I need. Its also useful to have first cut and plug - i.e. slow taper and hardly any taper at all. You can get First, Second and plug, but its not necessary for most modelling jobs.

So, 2 each of 12Ba, 10BA, 8BA and maybe 6BA (depending on what scale you model in) may well do most jobs. I don't use sets because I'm bound to break one and spoil the set!

Mike
 
eastsidepilot

eastsidepilot

Western Thunderer
I only work in 7mm scale so I tend to only use B.A. sizes 6,8,10,12,14and 16. The 6 is handy for re cutting Slater's axle threads and the 10 for crank pins and bushes, and a couple of metric sizes, 1.5 and 2mm.

Proops are selling some really cheap B.A. taps.

Col.
 
JimG

JimG

Western Thunderer
Mr Grumpy said:
hi,
I'm hoping to expand on my tools and would like to purchase some taps & dies.
Please can anyone pass on some info as to the most apropiate sizes to buy?
Either BA or metric?
I noticed boxed sets vary in price from around £150 to £250, so I want to be sure to get it right!!
Click to expand...

Richard,

In the UK go for BA (which is a metric system :) ) since there is a plentiful supply of screws, nuts, taps and dies. Don't get boxed sets since you will probably never use half of the contents. For railway modelling you will probably use 6, 8, 10 and 12 BA. Don't bother with the odd sizes which are not preferred. Get a taper and a plug tap for each size, and a die. Some people say that you have to get HSS taps and dies but they cost a lot and carbon steel taps and dies work well for the occasional modelling use. I'm using carbon steel taps which I've had for over thirty years and they are still cutting well. Also, dies are not a top priority since I find the majority of work is done with taps to use with purchased screws. Also get drills which will give tapping and clearance sizes for the BA sizes you want. If you already have a set of metric drills from 1mm - 3.5mm in 0.1mm steps them you are pretty well covered for 6BA to 12BA.

If you want smaller than 12BA, then there are 14BA (approx 1mm diam.) and 16BA (approx 0.75mm diam.)

Use a pin chuck for the taps as far as you can since you can feel how the tap is cutting and avoid breakage if you attempt to force it too much. Using a lubricant helps as well. I got a dollop of Trefolux from an engineering friend many years ago and I'm still using that. :)

Jim.
 
Dog Star

Dog Star

Western Thunderer
Taking Jim's post, I rarely use the 6BA and 8BA dies... however, the 10BA and 12BA dies do get used and almost as often as the corresponding taps. For example, JLTRT wagon buffers come with a collar which is (meant to be) soldered to the buffer ram to retain the buffer in the stock... I run a 12BA die up the tail of the buffer ram casting and then use 12BA nuts to adjust the distance of the buffer head from the headstock.

Try to get into the habit of using a cutting fluid and always when cutting a thread in whitemetal. I have a small pot which contains white spirit and a few drops of light oil, dip the tap in the pot prior to putting the tap in the hole.

Jim mentioned the use of drills for tapping and clearance holes... see if you can get a table of drill sizes such as a Zeus Precision pocket book. If you are going to work with (say) 12BA taps then the correct tapping drill is 1.05mm diameter and Squires keeps that size as a stock item. Buy a packet of ten and you will never break one!
 
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oldravendale

oldravendale

Western Thunderer
I use my BA taps and dies quite a bit - and sizes from 8 or 10BA down to 16BA. I've used them for years and only just broken the first one - a 14BA. I can't remember how - I think I was making a short cut and failed to lubricate it. I use the dies to clean the threads up on lost wax brass threads - a good example is the castings for couplings by CPL.

I also have to admit to buying a set of small sized metric taps and dies - very inexpensive at about £35.00 as they are used so rarely, I believe it was from Amberly Services. DJH tend to use metric screws and fittings and I've just built two locos so it was worth my while. They work OK, but for the amount of use they'll receive it is not worth spending large money. However, to start with I'd buy BA taps, 10BA and smaller. You can always get other sizes and any dies you may need as single items.

Brian
 
SteadyRed

SteadyRed

Western Thunderer
eastsidepilot said:
I only work in 7mm scale so I tend to only use B.A. sizes 6,8,10,12,14and 16. The 6 is handy for re cutting Slater's axle threads and the 10 for crank pins and bushes, and a couple of metric sizes, 1.5 and 2mm.

Proops are selling some really cheap B.A. taps.

Col.
Click to expand...

Those taps at Proops are really good value.

Dave
 
adrian

adrian

Flying Squad
I'd agree with all that has been said already - especially regarding even BA sizes. I mostly use 8,10 and 12 for 7mm and 2mm modelling - occasionally 14BA and 16BA. I do have a 4BA set but only used that for making tools and bits and pieces not modelling.

The only exception which nobody else has mentioned is 9BA - I have found this useful on a number of occasions as the clearance diameter for 9BA is 5/64" - so for example I can make crankpins from 5/64" steel rod, run the die over the end of the rod and then run the tap through a 10BA nut - hey presto instant crankpin and nut.
 
Mr Grumpy

Mr Grumpy

Western Thunderer
Many thanks for your sound avice chaps!
I was wondering about the metric ones as I have almost completed my DJH 47, and as Brian says, they also use metric screws and nuts.
I'm hoping to get hold of a MOK 9f if any are left over from he waiting list, and from reading several threads, it looks like I may have to tap the occasional thread.
Many thanks again,
Richard.
 
oldravendale

oldravendale

Western Thunderer
As you say, that is indeed inexpensive. However you have sizes from 0BA in that set which you'll never use. Personally I have used 6BA all the way down to 16BA, in even numbered sizes (but note Adrian's useful comment re 7BA above), but you'll rarely need anything bigger than 8BA. The Axminster set doesn't go small enough for our sort of stuff either.

It may be worth calling Amberly Services to see if they have any small sized sets of BA taps & dies. I have their number somewhere if that will help - let me know. As mentioned previously, Proops are worth a shot, although in my experience they don't do the really snmall ones. The other options are Eileens who usually have a good range in stock but are expensive, or Squires - a good range and relatively inexpensive. I suggest that these are probably adequate for the sort of work we do. Also, once you've ordered £15.00 worth of goodies postage is free. You'll find them on Page 98 of their catalogue - http://www.squirestools.com/files/12-06x.pdf

I bought a replacement 14BA tap from them recently and it's certainly adequate for the sort of work I am doing.

Brian
 
Dog Star

Dog Star

Western Thunderer
Here is a cheaper alternative to Axminster...

BA 0, 2, 4, 6, 8, 10

You could check the BA taps and dies section of the site to select only the items that you feel are desirable at this time.
 
JimG

JimG

Western Thunderer
oldravendale said:
Whoops - sorry! I'd heard 7BA mentioned somewhere else, then - certainly in conjunction with valve gear but memory now fails me.
Click to expand...

Brian,

5BA and 7BA are popular with model engineering since they are - as near as dammit - 1/8" and 3/32" diameter over the threads. Also I think I remember from pre-metrication days that odd BA sizes were popular with the engineering trade and the even BA sizes were popular with the electrical trade - or that might have been the other way round since the memory is getting dodgy. :)

Jim.
 
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