Tap and die advice please

Hi there,
Fiddling around practicing to become a model engineer and
having now mastered cutting and filing bits of metal my next stage is to do
some tap and die cutting.
Now what sort of metals do I need to make nuts and bolts.
and what tap and die set should I get?
I need some mini ones for ME and a big set up to 10mm for my Stationary
Engines.
and other bits and bobs.
I have a budget of £120.00
Thanks
Colin J
Reply to
Colin Jacobs
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Unless your into European engines my guess is you will need BSW Taps, common to most English engines, American engines use UNC. I would go for the HSS ones, a good scource of supply would be:-
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They will also supply your ME taps and dies.
Regards
Andy
Reply to
andyengine
Look here for your tapping sizes
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Reply to
nick
Colin:
Model Engineers use 40TPI threads for scale appearance.
Other than that, BSW and BSF will be useful, Metric and UNC/UNF threads are of limited use in your environment.
Peter -- Peter & Rita Forbes Email: snipped-for-privacy@easynet.co.uk Web:
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Reply to
Peter A Forbes
Cheers. I have now been on the Tracy tools web site and what is the difference between fine and coarse sets? Do these sets have the three taps needed for each hole?
Reply to
Colin Jacobs
If you are tapping blind holes the set of three (taper, second and plug) is useful - the taper tap is a must for starting a thread in a hole as it both guides the tap to enter straight, and doesn't offer too much initial resistance - if only contemplating nuts a taper tap will form a full thread provided the nut isn't too thick.
The use of a lubricant such as Trefolex is beneficial when cutting threads with taps and dies.
The Workshop Practice Series book on Drills, Taps and Dies offes much information on this subject at resonable price.
John Ambler Sussex, UK Return E-mails to snipped-for-privacy@skiprat.net
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Reply to
John Ambler
Tracey Tools is pretty expensive................the best place for a good tap and die set is Ebay!
You can often get very high quality pro sets, s/h, that have been cleared from engineering shops, at a lot less than the Chinese stuff you get new nowadays.
k
Reply to
Kevin Johnston
The difference between fine and course is just that. for the same size thread, fine will have more threads per inch than course. These may or may not be within a standard series. For tapping, a taper tap is essential. A plug tap is necessary when tapping a blind hole. A second tap is nice but in'st essential. Your best bet to learn all of this is to find someone who knows and talk to them. There's little substitute for trying it yourself. Do colleges still offer metalworking classes? If they do, try that. A number of semi retired craftsment I knew used to teach evening classes. Alternatively, find a club or organisation that specialises in old machinery and talk to some members. Stationary engine, tractors and vintage car clubs are freqently a good start.
John
Reply to
John
Go and search uk.d-i-y This question has been asked and answered well several times.
Taps are useful, thread-cleaning dies and thread-cleaning files are useful, thread-cutting dies are nowhere near as handy. You just can't practically make nuts and bolts yourself - you buy them. Nearly all the thread cutting I do is tapping holes into big lumps or even thick sheet to take a bolt. Turners might do a bit more thread cutting in the lathe (a good place to do it). As a way of making threaded rod, then it's just a better result if you roll form the thread (complicated machine) rather than cutting it. Nuts aren't worth the trouble as you can't hold them easily. Of course there are exceptions - brass nuts don't seize on exhaust fittings and decorative brass fittings are always handy. In general though, you'll be tapping holes, not using a diestock.
Threads come in different categories "coarse vs. fine" and "Brit vs. Yank vs European" British coarse and fine were BSW (British Standard Whitworth) and BSF (BS Fine). Yank were UNC and UNF (Unified). BSW kept going for some years but BSF evaporated very rapidly after WW2 in favour of Unified threads. I remember Dad scrapping literally wagon loads of BSF tap and die sets - there was a vast pile of them at one time, a couple of ton of unrusting steel sat in a corner of the yard. If you need any of these, buy them S/H -- they're still around easily enough.
As for a thread system to actually use, then go with metric. Buy yourself top-grade Presto tap sets of three taps, as and when you need them. As we no longer use so much low-grade cast iron, the metric series de-emphasises the coarse thread standards and mainly uses a single set of pitches.
Then there's the weird threads, like the 26tpi (threads per inch) brass industry thread that used the same pitch for everything, because it grew out of Victorian hand-chased threads cut on lathes with manual toolrests. Also the range of tapered pipe fitting threads, electrical BA threads (British through and through, but actually metric) and the finickey 40tpi model engineering threads that tear up soon as look at them. You're likely to encounter all these eventually, but don't rush to buy expensive new tools.
You'll also need a Zeus pocket book to look up the size of the tapping drill you should have used, but which you don't own and so had already bodged without. But you need one of those anyway, just to fill out the pocket of your brown dustcoat.
Reply to
Andy Dingley
If I'm doing sheet, or soft materials like aluminium, then I usually start with the second and not the taper. I don't need such a gradual taper as I might for a deep hole in steel, and taking more of a "bite" on each cut means I'm less likely to slip and damage it by accident - easily done in ally sheet.
The right cutting compound (squirt bottle of RTD usually) and the right back-and-forth action are also important.
Reply to
Andy Dingley
Thanks for the tip.
BugBear
Reply to
bugbear
As in UNF?
This would explain why even my (rather splendid) local supplier couldn't supply 3/16 BSF bolts.
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(web site down at the moment) I needed them to repair a sliding patio door.
(eventually found at a double glazing company).
I also realised (browsing a thread table) that 2BA is rather similar to 3/16 BSF
BugBear
Reply to
bugbear
There are a number of threads at that size.
3/16BSF = 0.1875" x 32tpi 2BA = 0.1850" x 31.4tpi M4.5 = 0.1772" x 33.87tpi 10UNF = 0.19 x 32tpi 3/16BSC = 0.1875" x 32tpi 3/16CEI is the same as 3/16BSC as the BSC series suceeded the CEI series. For a modern structure, I suggest what you needed was M4.5
John
Reply to
John
Yes. Take a look at some '50s or '60s ex-mil scrap / surplus. Chances are you'll find a deliberate placard on it saying "This equipment uses Unified threads". You might also see a series of adjacent circles stamped down one face of a nut (particularly on pipe fittings) to note it.
I forget the details, but Whitworth and UNC either don't fit at all or interwork quite well (camera tripod bushes). BSF /
UNF OTOH are close enough that a careless erk can easily gorrilate something by using the wrong fastener.
Reply to
Andy Dingley
Good grief!
BugBear
Reply to
bugbear
Discontinuity at 1/2" IIRC, otherwise pitches are the same.
5 degree difference in thread angle.
IME those are very loose fits anyway, and only 4-5 threads.
Plenty of "tolerance"
BugBear
Reply to
bugbear

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