[rocwoodwind]

Hello everybody, so I am devoting some of my fat stimulus check to the repair bench, including purchasing some of the necessary taps and dies for fabricating rods, etc. My question is in regards to the quality of the taps and dies I would get from Ferrys or voter for example. Are they high-quality where I can feel confident that they will last me a long time and do the job with precision and consistency at a high-level? I’ve been looking at other high-end websites like McMaster Carr and others, and their prices are significantly higher compared to Ferree’s, which may or may not indicate higher quality. Are the other tech’s out there who use taps and dies from Ferree’s happy with the performance?
Thanks!

 

[saxoclese]

Rather than buying sets I just started out buying the sizes when I need them. That means my sets have pieces from several different vendors including Ferree's. I have had a few problems with dies marked China and with the smallest taps breaking which is common. You could call Ferree's and ask where their taps and dies are made. Generally the price is a good indication of where they are made and the quality of the steel.

 

[smash]

I recently bought a few dies from Ferree's. They were made in China but worked very well. I only made one rod so I suppose the jury is still out on how long they will last!

 

[clarnibass]

Price can be an indication of quality, but there are some inexpensive and good taps and dies. One big difference is carbon steel or HSS. If I remember right, all of them from Ferree's are made from carbon steel. HSS lasts much longer which is its main advantage. Also if it's really HSS, it's usually anything from ok to very good. Carbon steel taps and dies can be good or terrible.

My approach is...
If you only need a couple of sizes and going to make just a few rods, get decent HSS ones. The price difference shouldn't be huge for only a few.
If you plan to eventually have many sizes and add making rod/pivot screws and (re)tapping as a "tool" that you can use, get good HSS ones. It's worth it in the long run.
Only get something cheaper if you absolutely can't afford anything more than that, or if a specific size you want isn't available in good quality HSS.

FWIW I've only ever had two dies break. One Japanese HSS, one Chinese and (supposedly) HSS too. Reason was they were the type with larger holes, more flexibility for adjustment, adn both broke when adjusted to open a lot.

 

[turf3]

Re: Tap and die quality at Ferree's?

Well, McMaster-Carr is hardly a "high end" supplier. However, they charge more because they ship the same day and keep huge stock.

Taps and dies are cheap enough that you should not in my opinion buy off brand "import" or unknown stuff. A bad tap or die can really wreck a workpiece, especially in the tiny sizes used in instruments. Ever break off a tap in a workpiece? Hoo boy.

Personally I buy all my metal cutting tools from MSC Supply. However, if you buy from McMaster (and don't buy the cheapest choice) you'll be fine too.

Places like Ferree's if they're selling at lower prices than metalworking supply houses, you've got to ask why. They have to pay for the tool, the local distributor's profit margin, and then their own profit margin. That means the original purchase price of the tool can't be very high. Quality is likely to be hit or miss.

(For reference, I'm not a professional woodwind tech, but rather a practicing mechanical engineer with 35+ years of experience in design and manufacture of mechanical products including extensive machining operations.)

 

[rocwoodwind]

OK great, thank you guys for your input. I definitely want to run this by people that I’ve been doing this a lot longer than me. I am buying these taps and dies with the intention that I will be using these over and over again for, well, my career. Especially the ones needed for the Conn’s, Buescher’s, and King’s of the world.
So I definitely won’t skimp on the quality, I’ll make sure I get high-speed steel, and I’ll expect to pay about $30 for each it looks like, or more. I will call Ferree’s too and ask them where they get their taps and dies from. We’ll see what they say. Thanks again everybody!

 

[clarnibass]

OK great, thank you guys for your input. I definitely want to run this by people that I've been doing this a lot longer than me. I am buying these taps and dies with the intention that I will be using these over and over again for, well, my career.

In that case definitely go with good quality HSS.
One die might cost $10 and another might cost $60, depending on many things, including how unusual the size is.
Also consider adjustable vs. non-adjustable. The former has the obvious advantage, but are harder to find in good quality (I've only seen Chinese ones and good Japanese ones that are not so easy to find). At least locally, the only good quality dies are non-adjustable and German made.

For taps, probably also go for good quality HSS. They usually come in sets of two or three (for one size), with a starter tap and a finishing tap. It's worth getting that instead of just one, but it depends. If your starter tap has complete threads towards the end, and you have enough access to get all the way there (also the length of the thread), then that might be enough. Or you could get away without a starter tap. Still worth having a set. Regular good HSS taps are generally made for steel but work fine for copper alloys used for instruments, especially for non-demanding re-tapping.

I would get everything when you need it as opposed to any set. I once had to tap aluminium bronze and even an excellent cobalt spiral tap couldn't do it (regular excellent quality taps were far worse). I had to buy a special tap for that material. Luckily copper alloys in instruments are much less demanding.

 

[turf3]

Personally I would buy a taper and plug tap for whatever size you need (the set of three with taper, plug, and bottom taps might be cheaper than two pcs. a la carte, but the only place where you would possibly want a bottom tap on a woodwind is those tiny screws for flat springs - but boy it sure would be easy to snap off a bottom tap in those tiny sizes - I'm not even sure that bottom taps exist in such tiny sizes). I would buy TiN coated for longest wear. And I would buy at least two identical ones for any size #4 or smaller (say M3 or smaller) in case you break one off. With the rapid shipping from McMaster-Carr or MSC you should be fine to just order the sizes you need when you need them.

I would also buy thread gauges both metric and English. Don't skimp too much on these. You won't need the super wide range of gauges for woodwind work.

While you're in there it might not be a bad idea to buy a bunch of little machine screws and nuts in the range of sizes of woodwind screws, just because sometimes you need to use a functional gauge to make sure of a thread size. If you'll keep them in their little labeled bags these screws and nuts can make reasonable thread gauges at trivial cost.

Don't forget tap drills either. I just go ahead and buy TiN coated as the default for any small size twist drill as the points often aren't all that accurate and they need all the help they can get to remain sharp. For the tiniest ones, you'll probably need to buy the little micro-chuck that you chuck the drill into, and then chuck THAT into the drill motor, because most Jacobs chucks have a little gap in the center where the three jaws come together. This gives you better holding power with large drills, but it means there's a minimum size you can chuck up.

You'll want to get a selection of good tap and die handles too. Sometimes one won't fit into a restricted space and you'll need to use a different one.

And finally, I recommend printing off a big chart of drill, tap drill, and thread sizes. You can find these on the net. Of course I couldn't survive without my 36 year old copy of Machinery's Handbook but it't a big book with a lot of other stuff that may be irrelevant to your needs.

 

[saxoclese]

I copied the chart from the Allied Catalog that gives the correct hole size to tap a "domestic" thread and the correct diameter of drill rod to cut threads with a die so that is not a problem. However, I have never been sure of how to find the correct rod diameter given the metric thread size marked on the die. Can someone explain how to do this? Thank you.

 

[turf3]

I'd go to Machinery's Handbook. You can probably get a used copy from Amazon for short money. It's all tabulated according to thread size and thread class.

 

[clarnibass]

However, I have never been sure of how to find the correct rod diameter given the metric thread size marked on the die. Can someone explain how to do this? Thank you.

Not sure what you mean... the threads are sometimes (often) smaller diameter than the rod, so you need a rod larger than whatever the die/thread is anyway.
If you meant the outer diameter of the thread itself, that's easiest with metric. It's marked Mx where x is the diameter in millimeters. For example M2 (or M2.0) is 2mm, M8 is 8mm, M20 is 20 mm, etc.

 

[clarnibass]

Re: Tap and die quality at Ferree's?

Personally I would buy a taper and plug tap for whatever size you need (the set of three with taper, plug, and bottom taps might be cheaper than two pcs. a la carte...

Sets of threes sometimes have bottoming taps but often have a tapered tap, "tweener" and plug tap. Just about all the hand tap sets I have come this way for whatever reason (some come in a set of two without the tweener). I guess the tweener isn't really necessary, especially for instrument repair, but it's often available that way so... yeah...

 

[Figaro]

FWIW I've always had good results with anything from McMaster Carr. I buy a lot of stuff from them for my auto repair shop. Good quality and fast shipping.

 

[saxoclese]

Not sure what you mean... the threads are sometimes (often) smaller diameter than the rod, so you need a rod larger than whatever the die/thread is anyway.
If you meant the outer diameter of the thread itself, that's easiest with metric. It's marked Mx where x is the diameter in millimeters. For example M2 (or M2.0) is 2mm, M8 is 8mm, M20 is 20 mm, etc.

Ok so the rod diameter of a Mark VI is .110" or 2.8 mm. The thread size is 2.5 x 0.45. So does that mean the rod diameter needs to be turned down to 2.5mm to cut the threads? Is it that simple?

 

[turf3]

OK, so you have a 2.8 rod and you want a M2.5 x 0.45 thread.

Machinery's Handbook shows the ISO standard threads as follows:

Class 4h: major dia. 2.500 +0 - 0.063 (2.437~2.500)
Class 6g: major dia. 2.480 +0 -0.100 (2.380 ~ 2.480)

You'll need to turn down the OD of the rod in the threaded area. Personally I'd target something like 2.450, so you don't have excessive force required to cut threads with a die.

As I noted above, if you're going to be doing mechanical work/machining work it's awfully helpful to have a copy of Machinery's Handbook to answer questions like these.

 

[clarnibass]

Ok so the rod diameter of a Mark VI is .110" or 2.8 mm. The thread size is 2.5 x 0.45. So does that mean the rod diameter needs to be turned down to 2.5mm to cut the threads? Is it that simple?

Yes, exactly the same as you would do for imperial threads.
Obviously you never want the threads too loose of a fit, but musical instruments generally have threads on the loose side and fit isn't as critical as for some other tools.

If you are not used to metric, once you know the metric thread, convert to inch, check what is the closest inch thread, then use the same proportion of spec size to actual diameter.
For example, if you need an M2.5x0.45mm thread, closest inch size is 3-56 (essentially the same, M2.515x0.454mm). So check what diameter you would have the rod for a 3-56 thread and use that. The inch diameter for a 3-56 thread is 0.099". Let's say you would make it 0.0965", the difference is 0.0025" (or 0.0635mm), so reduce the actual diameter (2.5mm in this case) by that amount. This is just an example and has measurements down to microns, which is far more accurate than instrument threads need to be anyway, so it's all approximate.

 

[turf3]

Further to that: in die cutting threads, especially small threads, you don't want to start out with the rod at (or, worse, above) the tabulated major dia. for the thread, because the cutting force will go up enormously. Dies aren't really designed to cut on the tops of thread forms. If you were turning the threads on a thread cutting lathe (probably the way they were made at the factory) then you just keep feeding the single point tool in until the thread meets size (in factory work you'd check every 50th part or so with a go-no go thread gage; in repair work making one you're not going to do that). You can tell if the thread on the end of a rod was originally lathe cut; it'll have a short section of reduced diameter at or smaller than the minor diameter of the thread; that's the relief groove where the single point tool runs when you disengage the thread cutting lead screw before you back the carriage out to make the next cut.

If you have an adjustable die, then you can adjust thread size using that feature.

For making a single rod to go in a single place in a single musical instrument, I'm thinking the best plan would be: turn down the OD of the rod to halfway between max and min major diameter, as per a tabulated chart; use an adjustable die (if available in the size you're working); and use the adjustability to bring the thread down till it just fits in the post of interest, or if that's not applicable, into a standard hex nut of the thread's size. You, unlike the factory, don't have to worry about parts being truly interchangeable.

 

[clarnibass]

Re: Tap and die quality at Ferree's?

If you were turning the threads on a thread cutting lathe (probably the way they were made at the factory) then you just keep feeding the single point tool in until the thread meets size (in factory work you'd check every 50th part or so with a go-no go thread gage; in repair work making one you're not going to do that). You can tell if the thread on the end of a rod was originally lathe cut; it'll have a short section of reduced diameter at or smaller than the minor diameter of the thread; that's the relief groove where the single point tool runs when you disengage the thread cutting lead screw before you back the carriage out to make the next cut.

Not that it's that important for instrument screws... but from screw machine shops I've seen, small screws like these are almost never single point cut. The tool is usually a bit similar to a die, coming from the "front" (tail stock end) to cut, even if it is coming from the side. With CNC, or even manual lathes setup specifically for this, barely any relief is needed, though many times they do have a relief.

For making a single rod to go in a single place in a single musical instrument, I'm thinking the best plan would be: turn down the OD of the rod to halfway between max and min major diameter, as per a tabulated chart; use an adjustable die (if available in the size you're working); and use the adjustability to bring the thread down till it just fits in the post of interest, or if that's not applicable, into a standard hex nut of the thread's size. You, unlike the factory, don't have to worry about parts being truly interchangeable.

Yes, though in reality, the adjustability is only (or almost only) important for non-standard threads. Most threads are a standard size and a non-adjustable die gives a great fit. With an adjustable die, you turn the adjustment screw until it just touches the other side, which pretty much gives the result of a non-adjustable die.
That said I also recommend adjustable dies (if you can find good ones) since occasionally threads are non-standard in weird ways.