Sorby threading tools

Hello Eric,

It takes a lot of practice to master using hand chasing of threads. I remember my struggle to learn how using what I thought was hard wood. Then I reread the book and discovered that their definition of hard wood was stuff like boxwood, African Blackwood, Cocobolo, etc. I tried some Cocobolo and turned the lathe by hand and wow I got a thread. I wrote an article for Woodturning magazine about making threads while turning the lathe by hand. It was published in the June

1997 issue.

I subsquently wrote a book on making threads in wood that was published in June of 2001. The name of the book is: "Making Screw Threads in Wood." It covers making threads with chasers, with threading jigs, and even laying them out and cutting them by hand. The book was published by GMC Publications in England and is now in its second printing. You should be able to purchase if from Amazon.com.

I should also mention that Allan Batty has a video out on hand thread chasing. That also would answer most of your questions.

Fred Holder

I don't have a book to sell you but I have one and use it so here are my tips. I had a Sorby Corp. demonstrator show me how to do it himself about a year ago. First of all, have you seen these instructions?....

're probably the same that came with the tools. I got mine at thedemonstration and didn't get any paper instructions. I wish they'd put outa video but I don't know that you could get much out of it anyway. Some of the tips given to me...

1) Slower is better. I prefer around 200 rpm. I can "feel" the threads forming easier this way.

2) Harder is better. Hard woods with, especially, tight and interlocking grains are best. French Boxwood (ie the plastic wood) is what the demonstrator used and I've found nothing better. Of course, you can't make everything out of that but it's fantastic to practice on.

3) Get the feel. Develop a rythm as you form the threads. Make several small passes AFTER you make the initial somehwat heavy first pass. That heavy first pass needs to be right on so that your next passes have something to hold onto and guide them.

4) Make sure you have that relief at the back of the inside threads!

5) I don't like the tool support rest. Too many things going on at once with that extra tool. I prefer to use just the lathe's toolrest for the inside threads whenever possible.

6) My main problem is getting the male and female pieces (not the threads really) sized correctly. Take very accurate measurements and then oversize the male. You can always sand a bit and reform the threads if need be.

Other than that, the instructions on the website pretty much say it all. It just takes practice practice practice like anything else. Also, if you can find somebody who knows how to do it, it makes all the difference in the world to have them hand-hold you. You'll have it down in 10 minutes.

Good luck,

- Andrew

Did you not get the sizing gauge with your threading tools?

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M.J. Orr

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Yes, I did. I still have problems with sizing sometimes. I said it's my main problem with the tools but even that isn't a huge one.

- Andrew

I guess what I am asking is....if the gauge does not give you an ACCURATE measurement then ..... is the sizing gauge a waste of time/money?...................Just curious........

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M.J. Orr

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Ohh, ok. I misunderstood. The gauge (at least mine) does give an accurate measurement but it's the process of cutting the male thread cleanly and accurately the first time and not wasting away ANY wood (thickness) in the process.

This one of the reasons I mentioned originally of making things slightly "oversized"; cutting the threads and then sanding/re-forming the threads again to get the fit just right. If you can get the motion of cutting the male threads just right then the gauge is right on and you'll get a tight fit in the threads.

I think the sizing gauge is a must-have unless you have something that'll do the same thing already (metal working?).

- Andrew

Having been accused of having a book for sale, I felt perhaps that I should add a few more comments that may help you. This is an extract from an article that I wrote on the subject:

One of the ancient turning techniques that has been gaining in interest over the last few years is the art of hand chasing threads. I first became interested in this almost forgotten turning technique when I began reading Bill Jones' column in Woodturning magazine (the UK publication). I had never even heard the term before. Thus, began a search, in fact, almost an obsession to learn more about this topic and also to learn how to do it. I've been making threads in metal with tap and die for many many years, but the thoughts of freehand cutting threads on a lathe intrigued me. The road from hearing about thread chasing to actually chasing a successful thread was not an easy one, but the journey has been an interesting one.

The first stage of my journey was John Jacob Holtzapffel's book, Hand or Simple Turning, where he devotes a section to the tools for chasing threads and how to use them in making threads on hardwood and ivory items. I read the sections on making and using chasers and tried to make my own, an outside chaser, but it didn't work. Finally, I found a location that had a supply of used chasers for sale, G & M Tools in England. They sold them for $6.00 each or $12.00 per pair. I ordered several pairs and wound up with chasers for 11 tpi, 16 tpi, 19 tpi, and 24 tpi. They didn't work either. I decided it must be the speed, my lowest lathe speed was 500 rpm. I even tried using my Carba-Tec lathe and turning it by hand to get the speed down to a manageable level. Nothing seemed to work. I was almost to the point of giving up.

I re-read Holtzapffel's book, he says that chasers are used to cut threads in hard woods and ivory. He says, that a different technique was required for cutting threads in softwoods, I didn't see this at first, or at least it didn't regester. I began to rethink my definition of hard woods. I had been using maple and apple woods, considering them "hard wood." I had some cocobolo on hand, so I chucked up a piece onto my Carba-Tec turning the lathe by hand. I tried the 11 tpi chaser, thinking that the coarser thread would be easier to cut. I was wrong about that, but it worked anyway. I was elated and the journey continued with a search for more answers. I purchased one of Dennis White's videos that included a section on thread chasing and James Lukin's book, Turning Lathes, which also has a good section on thread chasing. Anytime I had some spare time to play and a piece of suitable hardwood, I cut a few threads. Incidentally, that chaser I had made in the beginning now worked also. I'm afraid my main problem was in the definition of what is "hard" wood.

I wanted to share what I had learned, so I wrote an article on this subject for the British Magazine, Woodturning. That article was published in their June 1997 issue and reprinted in Useful Techniques for Woodturners, one of "The best from Woodturning Magazine" series. In that article, I described chasing threads on a Carba-Tec lathe by turning the lathe with my left hand while I held the chaser with my right hand. It worked very well and I've cut a lot of threads in that manner.

Both Holtzapffel and Lukin were using treadle lathes. Before treadle lathes, turners had used springpole lathes. So, I graduated to my foot powered lathe, it is a spring pole type with a lathe spindle and a full three revolutions per downward stroke. Wow, this was even easier than turning the Carba-Tec by hand, I now had both hands to work the tool. I began to feel confident. Enough so that when I agreed to demonstrate my foot powered lathe at the January 1997 meeting of The Seattle Chapter of AAW, I included thread chasing. Since then, I often demonstrate this technique at craft shows when people ask how I cut the threads in one of my threaded boxes. I have now progressed to chasing threads at 500 rpm. I will admit, however, that a speed of 100 or 200 rpm would make it a great deal easier.

I share the above with you to explain how I got from hearing about thread chasing to actually doing it successfully. I'm sure the journey would have been much shorter had I been able to watch Bill Jones or Allan Batty demonstrate the technique. A chance that didn't come about until after I had finally learned to chase threads on my own.

First, you have to have a pair of thread chasers, one for the inside and one for the outside, as shown in Fig. 1 (This was a more difficult task when I began my journey, now you can buy them from several locations .). Incidentally, when it comes time to sharpen that chaser, hone or grind on the very top only. Bill Jones and Allan Batty both recommend grinding on the top of the chaser - never , ever grind on the face. I sometimes grind the top and sometimes use a diamond hone, either works well.

You also need a suitable supply of "hard wood". Wood that is hard enough for thread chasing is generally wood that will cut cleanly with a scraper: lignum vitae, boxwood, Osage Orange, desert Ironwood, redheart, African Blackwood (the best). I've also cut threads in oak, black locust, holly, and mesquite. I've even used a bit of Red Lable Hot Stuff CA Glue to harden apple wood enough to cut threads in it, but I don't recommend the softer woods. The key is a dense hard wood that will take and hold fine detail. This defined, let's get to making threads.

In all of the literature I read there was no definition as to which you should make first, the inside (female) thread or the outside (male) thread. Bill Jones didn't seem to think that it mattered, but Allan Batty says to make the inside thread first. He says that the inside thread is more difficult to make, because you can't see what is going on inside the hole. I agree with him. A lot of my thread chasing practice has been to take a 16 tpi chaser and make a thread to fit a 3/4" x 16 tpi nut. This was always a trial and error situation until I watched Batty demonstrate at Provo in June of 1997. He said to make your inside thread first and then on the end of the external thread to make a short tenon that just fits into the inside thread. This tenon is then the bottom of the external thread, when your chaser marks this area, your nut or box top will screw on.

Hope this explains the subject a bit more.

Fred Holder

I think Andrew tried to indicate that he was joking, but for those less familiar with Fred, I'd like to point out that Fred has never pushed his books nor the periodical he publishes (and I regularly write for) More Woodturning. As I see it, Fred was mentioning the book to point out that he has given a lot of thought to this topic, and has some credentials in the area (he has also demonstrated thread making to an international audience).

I'm not much into making threads, but I have followed the literature. Fred's book, and the chapter in Mike Darlow's (second, I think) book are the best available print resources on the techniques and equipment called for that I have encountered. I find the two presentations complimentary, rather than redundant, and recommend them to anyone wishing to regularly engage in thread making.

There are also a couple of good videos on the subject, though they are more specific to a particular method, while the written materials present the full range of means by which threading can be accomplished.

Lyn

Accused? Nobody had to accuse you of anything. You freely did it yourself.

"I subsquently wrote a book on making threads in wood"

Really? Could you provide some way ... any way at all to find this book?

"that was published in June of 2001."

Yeah, but so many books were published in June of 2001 concerning this topic.

"The name of the book is: "Making Screw Threads in Wood.""

Hmmmm I still can't find it in the library .... could you give us just a little more information on it?

"The book was published by GMC Publications in England"

Ahh, ok. Yeah, but how popular is it?

"is now in its second printing."

Sounds good! But where can the average Joe Slob.... like myself .... FIND it?

"You should be able to purchase if from Amazon.com"

Bzzzzt. What's the ISBN / Link / etc? Come on, Fred. Don't cut the pitch short.

But I wonder if you actually answered the original posters' question with that or simply provided a nice teaser for your book and/or article. This could certainly be considered a most masterfully constructed veiled accusation if you want. .... *cough cough cough*

On a more serious note, do you in your article/book or the Allan Batty video go into the Sorby Threading tools? Or should I just buy them to find out? ba-da-boom.

- Andrew

Well, let's see if this will help you out, Andrew:

Paperback: 144 pages ; Dimensions (in inches): 0.38 x 10.82 x 8.22 Publisher: Guild of Master Craftsman Pubns Ltd; (December 31, 2001) ISBN: 1861081952 Amazon URL:

(mind the wrap) Through Amazon, it costs all of the princely sum of $10.47.

Lyn

AHilt> Accused? Nobody had to accuse you of anything. You freely did it yourself. > >

Thank you Fred, this makes the threading thing a whole lot better and easier to understand, and I now know what I did wrong

Have fun and take care Leo Van Der Loo

Fred Holder wrote:

Thanks Andrew......................

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M.J. Orr

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Excellent Lyn. Thanks. Fred should hire you.

- Andrew

Hi Guys,

Thank you all for your help. I know what I have to do now. If I want to get this book, I'll buy it. Andrew your advices are precious as well. Fred I've been on your site. I was also told about Allan Batty's Video. Everything's fine. Cheers Eric

I think he does.

Don

"Lyn J. Mangiameli" wrote: Fred has never pushed his