Taps and Dies - Interpreting LH vs RH in their labels.

[rtropp]

I have been looking through Ed Tosti's book on building the Naiad. In the appendix he describes some clamps that I intend to make. They use taps and dies to make the threaded posts. For one set of clamps you need Left Hand and Right Hand threads.

 

On die sets, or many individual dies there is not LH or RH given. do the dies default to one kind or the other if not specifically called out... or am I just missing something?

 

Similarly, for taps, are there LH and RH and if so what might they be if not specifically labeled.

 

 

Finally, what would be the best diameter brass rod, and the appropriate drill sizes to create 6-32 and 4-40 threaded posts.

 

I have found a number of charts online but they can be confusing to a neophyte and was hoping to start off with the right tools and parts.

 

Thanks,

 

Richard

Edited January 30, 2014 by rtropp

[bizibilder]

Virtually all taps and dies are made for RH threads and they are usually not labelled.  LH taps and dies are specials and will normally have "LH" on the stem along with the thread size.  However there are many taps and dies that have no information on them!

This will give you tapping sizes (ie the size to drill a hole to be tapped):  http://www.shop4fasteners.co.uk/acatalog/UNC-Tapping-Drill-Sizes.pdf

For rod to be threaded the nominal size diameter is the one to pick.  Ie for a 6mm thread use 6mm rod (which will always be a little undersized anyway).

[Q A's Revenge]

Good advice bizibilder.

 

I plan to make some of those clamps as well at some point. I have a variety of metric taps but all of them were standard RH ones. The best deal I got for LH taps and dies was on eBay from a Chinese seller. Unsure how good they are yet but they look alright and they only have to cut brass.

[michael mott]

I have a few Chinese dies, I must say i am not impressed with them, I was just trying to thread a little mild steel with a 3/8 x 24 and I gave up because it would not cut. It worked fine as a chaser to clean a thread on a bolt though.

Most of my dies I have purchased as I have needed them in the past, and they are good quality ground ones and they cut beautifully.

 

Michael

[WackoWolf]

Michael,

 

    Where do you get your got taps and dies from, could you post a link please.

[Q A's Revenge]

For what it's worth Joe, the best place to buy tooling like this are engineering supply shops. They tend to sell only good brands. Having said that, they may be outside of budget at times! I have done the same as Michael and only bought the sizes as I've needed them.

[rtropp]

Does anyone know of a decent mail order site that would sell 4mm and 6 mm brass in the U.S.? I have found only 4mm on Amazon but cannot find 6mm in my searches.

The hits I am getting on Google mostly have theirs in fractions of inches which do not match up the MM equivalents. I would like to find a place that has some decent prices for brass, and other rod. Amazon can be pricey.

 

Thanks,

Richard

[Mahuna]

Hi Richard:

 

Try this site:

 

http://www.victornet.com/index.html

 

Frank

[rtropp]

Frank,

I contacted them and they cannot supply 4mm or 6mm brass rod.

I found 4mm on Amazon and ordered it but cannot for the life of me find 6mm.

I can find 1/4 but that is 6.35mm and I do not know if that would work with 6mm die.

 

If I continue not finding 6mm, and cannot use larger rod like the 1/4", I guess I will have to write off the tap and die I have for that size and buy a set to fit 1/4 inch which seems more readily available as stock.

It's funny because I can obtain 6-32 threaded brass, and they must be getting the stock from somewhere :-)

 

Oh well, it's all a learning experience.

 

Richard.

[Q A's Revenge]

1/4 inch brass rod won't work with a M6 die unless you can turn it down. For what it's worth I'm going to be using M4 for my clamps.

[rtropp]

QA,

 

I am getting confused with some of the nomenclature.

 

Is M4 similar to 4-40?

 

Luckily, I have been able to obtain the 4mm brass as well as the set of 4-40 tap and die, left and right, which are mentioned in Ed T's book. So I am good to go with those... I think. I guess I will find out for sure when they get here.

 

I agree will also use the 4 mm which should be enough to do the clamps shown in the appendix.

 

I think before I buy an additional taps or dies, I will first check to see what brass rod is most easily available. Seems like the 1.4 inch imperial and the 4mm metric are what I have seen most either on Ebay or at suppliers.

 

Richard

[Q A's Revenge]

We use mostly metric threads here in the UK. M4 is simply 4mm. I guess 4-40 is an American thread? I would just stick with the threads used in your area.

[mtaylor]

Richard,

 

Do you have metal lathe or drill press?  You can turn down the rod.  If using a drill press, use files.  Go to a fine file when you're close to the diameter needed.

[Q A's Revenge]

Not having made any of these clamps yet I don't know how easy they are to assemble but there are instructions in one of my woodworking books if you'd like a scan Richard. PM me and I'll see if I can attach it.

[rtropp]

QA, I am beginning to understand the differences. For future, I will first find which material is available locally, then purchase the tools to meet their standards. Luckily 4mm is easy to find and I have a place that will send 6mm. But, as I learn more about the whole tap and die process, I will be able to formulate some best practices for my area.

 

Mark,

My lathe is wood but I have a brand new mill just waiting to be used. I can understand the use of the file, and may have to go that route. I am still new enough to mills that I am not sure if one can be used like a vertical lathe. Not sure what accessories, if any are available, might be needed to accomplish that. If it were possible it might pay off if I can also turn brass cannon on a mill. Just not sure if it can be done and would be a good idea to try.

 

I am the kind that learns by doing some "useful" project. So I am about to embark on that journey. My two initial projects are a sled and push sticks for my table saw, and clamps using the tap and dies as well as table and jig saws.

QA If you can send the plans I would appreciate it and will PM you my email address.

 

Thanks to all

richard

Edited February 1, 2014 by rtropp

[rtropp]

Mahuna,

I emailed them and they said they could not supply those sizes.

Richard

[gjdale]

I have only the flimsiest grasp of how the metric vs "non=metric" notation systems work for taps and dies.  I get that the notation measures slightly different things, but..........   A search of the internet brings up all sorts of interesting information, but none that I've been able to find so far seem to give a very basic "equivalence" if you wish. For example, say you wish to find out what the closest metric size might be for a given "non-metric" size (e.g. 4-40, or 2-56 etc).  Does anyone know of such a simple comparison chart?  It sounds too easy, but clearly it isn't.........           

[Q A's Revenge]

I have seen an American thread chart that shows the major diameter as a metric measurement. That's probably the best you'll likely to get because most folks work in either imperial or metric and don't really need to know what you're asking. It's sounds like you really need two thread charts so you can compare sizes. If I can find any suitable charts I'll link them for you.

 

Edit. Thinking about this some more can I share my own thoughts on suitable sizes?

I have some store bought clamps with 105mm long jaws and they have M6 threads on the screws.

If you want to make clamps with metric threads then I suggest that M3 is probably the smallest size you'll likely to use unless you plan to make some really small clamps. For my own use I've chosen M4 as a start and if I want to make something a little bigger or smaller I'll try M5 or M3. For some of the imperial sizes mentioned you may need to go down to M2.5, M2.2 or even M2 though. Be aware that although M3.5 and M4.5 are available in standard right hand taps and dies you might struggle to get LH versions!

 

Although I use only metric threads if I could get suitable taps and dies at a reasonable price I would most likely use 1/8" and 3/16" Whitworth as they have a nice coarse thread pattern for faster opening and closing!

 

 

 

Some thread data here:

 

http://www.modelfixings.co.uk/thread_data.htm

Edited February 8, 2014 by Q A's Revenge

[rtropp]

QA,

That is an excellent link... very helpful.

 

I have gone around this a number of times and believe I am beginning to understand. I have ordered various size brass rods, sized both as inches and mm that would seem appropriate for the 6-32 and 4-40 taps and dies as well as the taps and dies themselves that are described in Ed Tosti's book.

 

In order to use those these I will have to reduce the diameter of the rods when they arrive. Not having a metal lathe I will experiment with using my wood lathe, hand drill or mill with a hand held metal file to size the rods for use as 4-40 or 6-32.

 

If that is too arduous an experience I will continue my experiments by searching for taps and dies that fit standard available stock without having to rework (file) them. It will have some cost but that will be the cost of the education. If this research becomes necessary, I should end up with brass rod samples in a range of sizes both inches and MM. Also a set of taps and dies in the range I think I will use (certainly not more than 1/2" or so. Then find a reasonably priced Tap/Die set to experiment with.

 

Anyway, that's the plan today. I will post the results of my first efforts with 6-32 and 4-40 when completed.

 

Richard

[Q A's Revenge]

Something else that may be of interest is the relationship of the parts. On my bought ones the jaws are around 28mm thick, the pin is 9mm dia and the thread is M6.

Or put another way the pin is 1.5x the diameter of the thread and the jaws are 3x the diameter of the pin. I don't think anything is tool critical except if the pin is too large the hole for it could weaken the jaws.

 

As you've found out though, working with stock materials available will be easiest.

[grsjax]

http://www.engineersedge.com/screw_threads_chart.htm

 

The above link is to a ANSI external screw thread size chart.  Only gives diameter in inches but easy enough to convert to metric.  BTW 4-40 is .1120 major diameter and 40 threads per inch.

[Q A's Revenge]

Post #18 has a link: http://www.modelfixings.co.uk/thread_data.htm

 

That has metric data (maj dia) for American threads, no need to convert.

[gjdale]

Thanks for that link QA - most helpful - and also for your thoughts and the ratios of various components. That all helps to make sense of it all.