Taps and die recommendation

Personally I won't buy carbon steel taps or dies, I think they're crap.

And you don't have to spend a fortune to get top quality HSS anyway, there's literally thousands of NOS ones available on ebay at good prices!

The good brands being Dormer, SKF, Osborn, Hall, Warrior, Guhring, and Presto (old).

If you absolutely must have brand new then Osborn Europa tool from GBR engineering are good value, or Sherwood brand.

Triangle and LAL., 2 more old names. Noel

Surely if the carbon steel tap or die is correctly and accurately ground then there is no reason for it to be of low quality even if it wears a little quicker. It’s the quality that counts more than the material.
regards Martin

Invariably carbon steel taps are not ground, maybe the flutes but not all over as per HSS.

Tony

If you are new to cutting threads, FWIW use Taps and Dies, but hand powered., but keep them aligned correctly with the work.

You do not want "drunken" (off centre threads, or trying to remove broken taps from holes. As you would expect, the smaller tyhey are the easier they are to break. Having said that, by misue and poor technique, I broke a M10 Tap. An expensive way to learn, thankfully, I managed to extract the remains..

(Too often a precursor to a scrap part )

Sod'slaw says that the Tap will break in the last hole, so keep it straight, lubricated and do reverse to break the swarf if a straight flute tap.

Howard

I have seen an idea somewhere, woodwork mag or YouTube, for drill guidance. It was 2 short thick pieces of wood fixed together at right angles to ensure square presentation of a drill on an electric pistol drill. Maybe this idea could be used, wood or metal, to start a tap square to the work. I avoid starting hand tapping. I often start the tap using mill or lathe then transfer work to bench vise for extra grip on 3/8in or M10 as I find work slips in 3 jaw. I also use 1in dia knurled wheels for small threads as shown above. Funnily enough, don't recall anyone busting a tap in School metalwork lessons. It was always pillar drill hole, put work in bench vise and start tapping with the usual wrench. Plenty of drunk threads when doing same with die and stock! Trefolex on steel, WD40 or paraffin on Ali. Sometimes use Guy Lautard's concoction which is very effective and good for blind hole tapping. It is 3 parts Olive Oil, 2 parts White Spirit and 1 part genuine Turpentine. Smells nice as well! Also use it for drilling holes. Tall narrow glass salad cream bottle for mixing up, transfer to small plastic dispenser bottles.

There you go, OP, bit OT by me and others but a wealth of useful info to get you started. Good luck.

Edited By DMB on 15/12/2022 23:04:48

I just discovered one drawback of cheap tap and dies sets: the hole and thread in the die is not always machined square to the body of the die! This gives a drunken die, which of course will only cut a drunken thread even if held in the lathe in a good die holder etc.

I discovered this when I picked up a die from a cheap set I had lying around and ran it down a commercially made bolt to identify the thread. It was the right thread, but as I spun the die onto the bolt, it wobbled out of true by about 1.5mm or more. Tried it on different bolts and set screws, same result.

A trap for young players!

Thanks for that Hopper. It's one variable I hadn't considered.

As the owner of taps and dies of various origins - not always identifiable - I am used to checking the finish on die threads. The makers occasionally fail to remove the attached cuttings from the relief holes which can make threading impossible. Having off center or out of alignment dies is something else to put on the checklist.

All in all though, with modern machine tooling taking over in most of our lower priced markets, quality is getting better and better. Where it still seems most prone to failure is where multiple manual processes and assembly are operations are involved ( lathe and mill construction? ).

One thing that does confuse me is why taps generally seem to be made to a higher standard than dies.

Pero

Probably less demand Industry would have use die heads or screw cut external threads now they would be done on a CNC with inserts. On small sizes taps are still quicker so CNC time is less than thread milling hence the vast array of machine taps now available.

Also a tap cannot be adjusted like a split die so has to be made to produce a thread to spec straight off.

Edited By JasonB on 16/12/2022 07:19:22

Yes it is the one variable you would not think of. I discovered it quite by accident a few days ago. The tap and die set was one of those old small sets sold cheaply in hardware stores in the past and I think probably made in post-War Japan when their quality reputation was not what it is today. I picked it up at a garage sale and have never actually used it to cut a thread. And now probably never will!

I think taps are easier to manufacture because you can grind the external thread easier than grinding the internal thread in a small die. Just like screwcutting, easier on the outside than inside by nature.

Yes, today's cheap tooling is getting a lot better. Stuff coming direct out of China is amazingly good for the price. I figure it is surplus industrial supply for their own factories so is industrial quality, not built-down-to-a-price "hobby grade" stuff. China certainly is not leading the world in manufacturing by messing about with poor quality tooling in their factories. Time is money and good tooling saves time.

What most do not appreciate is that there are always rejects, at some time/point in manufacturing industries.

If materials, like powders, foodstuff ingredients, even materials such as aggregates for concrete. They are simply blended with other streams in order to achieve a product within the specification. Not dumped, unless no other option is available.

Steels are adjusted atbthe melt stage, by analysis and addition of other matetials in order to adjust the analysis of each batch. Nothing is just dumped - if not good enough it would be adjusted for a lowerbquality product.

Take water in your tap. It is blended from different supplies if necessary. Supplies from reservoirs is taken from different outlets (at different depths) to be able to use as much of the contents as possible, without the quality deteriorating. Maximum usage from the supply available - but nothing unused, as far as possibly possible.

Plastic components, out of specification are not dumped - they are either used as lower specification products or recycled by shredding and re-use of thr materials. Experience, here, from injection moulding rejects. Food grade products must be from virgin materials, but things likebpaint pots can be made with previously rejected items. Nothing is dumped, if possible.

Now to model engineering supplies. A lot of industrial/commercial products are required to a high specification. Occasionally products will fall outside the acceptable strict specifications (batch starts and finishes, perhaps?). Where do they go - to the cheap end of the market, if possible, before the expensive alternative of remelting and going through the manufacturing process again. The chinese direct these to people who are satisfied with the lower quality or simply are gullible.

This not only applies to taps and dies. Sintered carbide cutter inserts do not all pass the strict industrial specifications, a lot are sold to unsuspecting buyers because they are cheap (no industrial user would accept them). It even applies to machines - buy cheap buy poor specced machines, where poor castings or machining mishaps on the production line are ‘bodged’ to build as cheap machines.

It’s not all gloom, however. Think, here, that worn machines, less than rigid machines and cheap, poorly specified machines would not get best use of highly specified cutters which would be used in highly specified machines - providing a much longer cutting life. So lower specced items can be used, as adequate quality of the product produced by the machinist can be attained with care. A completely different environment than the mass production market in industry! Where thousands of items may be expected before the product goes out of specification (and round we go, again, with sub-specification products🙂 ).

I think it's because we become demob happy. Having carefully made many threads, with glory one step ahead, our attention switches to celebrating a successful job. Whilst thus distracted Slack Alice takes over and breaks the tap...

Remember 'Friday Cars'? Vehicles bedevilled by small faults, and allegedly turned out by the last shift before the weekend.

Dave

I started collecting film cameras with former USSR ones and while quality control is always limited there is also the issue of the 'Vodka' camera taken after a too enthusiastic lunch!

The trick is to do the last hole first.

Remember 'Friday Cars'? Vehicles bedevilled by small faults, and allegedly turned out by the last shift before the weekend.

Remember, too, that if it is a cheap chinese tap, it will likely be blunt by then. Even more galling, if it’s only the last of two!

Edited By not done it yet on 16/12/2022 12:26:18

I think HSS ground thread is because it would be difficult to make them any other way. Carbon steel can be absolutely fine but bargain basement manufacturing cuts every corner available and so the cheapest rubbish will be carbon steel and poorly made. Finding good quality carbon steel is more difficult these days as the old reliable brands for CS are mostly gone and most of the recognisable good brands deal in HSS. I find the products supplied by the Tap &Die company to be fine although the picture is clouded by calling the material they use HQS which is carbon steel if you spark test it. It would be lovely if it was as simple as just buying HSS and everything would be wonderful but poor HSS exists so we are back to trusted brands and trusted suppliers. As taps and dies are a popular subject for an enquiry on this forum there are many threads and much information to be found with a search of the forum. A useful search box is to be found on the Home tab on the black horizontal bar above.

Mike

When I bought a small Stewart steam engine kit it had all the BA fittings with it, so I bought the required taps and dies from Chronos as all my other threading stuff is metric. Those I bought were nor expensive and worked for the small amount I used them, I also bought some ME kit to suit. Unless you are young and serious about building lots of imperial thngs then yes go HSS but otherwise good carbon steel will do.

Like hopper I have a very out of line die from a cheap set. as for the last thread drill the tapping size just a smidgeon bigger ? One point is to drill the tapping size to suit the job and thread engagement - 60%, 70% or 80% as even a TINY undersize will increase the torque needed to drive the tap and therefore the risk of breakage ! Noel.

There are good and bad taps and dies out there. Also there are carbon steel and HSS taps and dies out there. I don't think there is any connection at all between these the two statements.

Do not buy sets of taps and dies (that is, say, 0BA to 10BA including odd numbers tapers, seconds and bottom taps and associated dies in a smart, usually cheap, wooden box). This is just a waste of money. Making your Stuart 9 I think you will only need 5 and 7BA (or metric equivalent). I have the feeling that these sets are at the bottom of the quality range like cheap drill sets.

JA

Again it all comes down to what you want to pay, a 0-10BA tap and die set need not contain bottom of the line items. Take this one for example which will have good quality contents