Wood threads

[SHIPPERS]

Can anyone tell me if and where they have purchased taps for making wood threads, prefferably in the Melbourne area.
Considering an upgrade on the work bench and like the idea of wooden vices

[Gra]

seen them at carbatec

[Honorary Bloke]

Yeap. Stu said he got them at carbatec when he did his video on the subject.

[Woodwould]

Thread boxes can be quite expensive. If you don't fancy splashing out on a set, I might be able to help you. I can thread 1/2", 5/8", 3/4", 1", 1-1/4" and 1-1/2" however, I don't lend tools, but I'd gladly thread your vice components for you.

[SHIPPERS]

Thanks guys for the quick replies.
Will have a look at Carbi tec
WW thankyou for the offer. Will see how i go

[BobL]

One problem with timber threaded vices/clamps is getting enough torque onto the threads for the vice/clamp to hold without snapping the threads or the threaded rod. So, if you want to use wooden threaded vices I would recommend using at least 2" diam threads and using a tough interlinked grain timber. All the box cutter sets I have seen stop at 1.5" which will probably be OK for a small vice, 2" threads will probably need to be turned on a lathe.

The next problem is that timber on timber can bind on the a) threads and b) on the loading faces. a) requires smooth threads (not consistent with tough interlinked grain timber) and a regular waxing and b) requires some sort of bearing. I have used polyethylene successfully but it does creep under constant use and needs replacement every now and then.

I cut my threads quite tight to begin with and then work the thread back and forth to lightly compact the threads. If you start out with normal thread tightness the compacting and wear makes them slopply very quickly. Also watch out for moisture problems. For tapping some sort of lube is recommended. I use PBLO which also slightly swells the timber so I tap the holes first and then let the timber dry before matching the thread otherwise it will seem too tight and there is a tendency to thread the rod too small.

I'm not trying to put you off - I love wooden threaded stuff - just trying to highlight some of the problems for load bearing threads

[Woodwould]

One problem with timber threaded vices/clamps is getting enough torque onto the threads for the vice/clamp to hold without snapping the threads or the threaded rod. So, if you want to use wooden threaded vices I would recommend using at least 2" diam threads and using a tough interlinked grain timber. All the box cutter sets I have seen stop at 1.5" which will probably be OK for a small vice, 2" threads will probably need to be turned on a lathe.

The next problem is that timber on timber can bind on the a) threads and b) on the loading faces. a) requires smooth threads (not consistent with tough interlinked grain timber) and a regular waxing and b) requires some sort of bearing. I have used polyethylene successfully but it does creep under constant use and needs replacement every now and then.

Bob, I think the problems you describe are related; roughly cut threads can lead to, what in metal-working terms are called, 'risers' where stresses in the areas of flaws cause failure.

With the traditional type of ' thread box' (that Carpet Heck sell), the threads often turn out less than ideal no matter how well the V-cutter is sharpened and honed. Wood species choice does contribute to the final quality of threads.

I have used traditional thread boxes in the past for threading Beech and Walnut press stanchions, but I now have the Beall system which cuts the threads with a router bit and as a consequence, the threads are beautifully formed with a smooth, flawless surface. This fine finish results in much stronger threads.

My own face vice employs twin 1-1/5" Merbau screws in conjunction with Vic Ash 'nuts' which frankly, see a fair bit of abuse. The surfaces of the screws are dense and polished through the merest application of wax and work extremely well.

In use, I often wind the vice chop out a nominal amount and then just use the RH end of the vice and the RH screw as you would any vice. I would have no hesitation in recommending 1-1/2" wood screws for even a single screw vice.

Merbau is a coarse-grained timber and as the threads seemingly hold up well in it, there shouldn't be any issues cutting threads with the Beall unit in similar or closer-grained timber.

[tea lady]

I've still got another bit of Merbu here that could do another wood screw.

[IanW]

By sheer coincidence I spent the weekend having some big screws! The wooden kind, of course.

Bob, I agree with you 100% that 2" screws are the most suitable for vises, but I think you may be being excessively fussy about fit. However, maybe your experience is different from mine. I've been a wooden thread enthusiast since I first 'discovered' them about 30 years ago, and have used them a lot for clamps and tail vises. The screw in my own bench has done yeoman service for at least 23 years, despite having 3 big moves to quite different climates in that time & shows no sign of wear. I always try for a neat, but easy fit - takes a bit of experience & knowing your woods & how they are likely to behave with the moisture cycles, but there seems to be a fair tolerance range. One thing I would advise is to avoid the temptation to over-lubricate them both when cutting & in use. Once a year or so, give them a wire-brushing, apply a good wax polish & then polish it dry. My tail vise screw is a chunk of Rosewood (Brazilian - might seem like sacrilige, but it's a long story, & it makes a lovely screw! ) which gave a fine & slightly oily surface. There are several woods here in Aus that work beautifully, my favourite to date being Bull Oak (C. leuhmanii), but Belah (C. cristata) is also very good - both damned hard to dry in the sort of sizes you need for bench screws, unfortunately. Lots of others work well, however (see below!) and Frank Weisner, a wise old craftsman from Europe uses Vic. Ash successfully, despite its (to me) very fibrous nature. I have no problems with strength - you would be flat-out stripping a well-made thread, & I've won bets with my 3/4" handscrews that you can't strip them (of course snapping the compression screw by tightening off-parallel is another matter). I regularly lean on my tail vise screw very hard, & so far it has copped all I could throw at it.

And I'm 100% with Woodwould that traditional threadboxes are useless with most of our over-hard woods - the router method is the way to go. My carbide bit has cut many metres of clean threads in woods (like Bull oak) that would simply destroy a thread-box. But don't squander your hard-earned on the grossly overpriced commercial product - you can make your own for nothing in 10 minutes.

Here are the screws I made over the weekend - been saving a few choice bits, & had a recent windfall (literally!) of river oak (C. cunninghamii). From the left they are River. oak (quite good to turn & thread & should be durable - supposedly the preferred wood for bullock yokes) next is Bull oak, the cleanest & toughest of all I've tried - have had some bar clamps with Bull oak screws for about 20 years & they have held up very well. The next is Brigalow (A. harpophylla). Lovely to turn (nice smell!) & threads beautifully, but have done a couple of Brigalow screws in the past that had the nasty tendency to lose big chunks of thread for no apparent reason - I hope it was just the particular tree or piece.

The next (pale one) is 'Idunno' wood, but may be Moreton Bay Ash (E. tesselata). It is a bit of a 4x4 veranda post that came off the house a year ago when the new deck was added. Turned & threaded nicely, & should be ok.

The last is Ironbark - not sure which particular one, as it was given to me, but probably western silver-leaf. Mongrel stuff to turn - picks out even with razor-sharp tools, but threaded ok, & should be a good user.

My 4c.

[Woodwould]

Very nice work (as per usual) Ian. I really must get to grips with more Aussie timbers. Is that Bull Oak a relatively common timber, or is it one of those go-for-a-drive-with-a-chainsaw timbers?

I've actually had better results on previous occasions with homemade metal-type taps and dies than I've had with traditional screw boxes.

The Beall units are overkill, but mine fell into my lap at a time when I wanted to make screws for my own vice, so I'm not complaining. They certainly wouldn't be difficult to make oneself as you say.

[IanW]

Is that Bull Oak a relatively common timber, or is it one of those go-for-a-drive-with-a-chainsaw timbers?

Hi WW. The latter, I'm afraid. The (not very big) tree has a wide, but patchy distribution in inland eastern Aust, in the 400-800mm rainfall zone. My stock (now virtually exhausted) came from two downed trees, one of which was killed by lightning, which caused a few splits & shakes in the wrong places. But even fresh trees (which in most states you are not supposed to fell) are hard to dry in large chunks. Worked into handles, it is just the best stuff outside of good Rosewood (Dalbergias, that is) I have handled. A bit tougher to turn cleanly, but it will peel nicely if you keep the skew ultra-sharp.

Of all the woods I have ever tried (too many to name) Apple wood is far & away the very best. It turns like butter & takes flawless threads, but is as tough as they come. I've got a pair of handscrews made from Apple & I reckon they'll last several more generations yet. If you could get hold of Apple wood in benchscrew sizes you couldn't go wrong, IMO. It will even cut ok with threadboxes, too.

I've actually had better results on previous occasions with homemade metal-type taps and dies than I've had with traditional screw boxes.

Don't know about using metal type dies, but I guess they might work on some woods. The taps are fine as long as they have a good taper, though the taps in general use are too fine for my liking. I like 4tpi for anything over 1.5" diameter, but NC/Whitworth in that size are 6tpi. I'm lucky to have a very good (& valuable!) friend who is a dab-hand on the metal lathe & has made me several, including my grandfather of a 2", which takes two people to drive through a piece of hardwood.

The Beall units are overkill, but mine fell into my lap at a time when I wanted to make screws for my own vice, so I'm not complaining. They certainly wouldn't be difficult to make oneself as you say.

I don't mean to knock the Beall threader - it does the job well & is easier to set up than a home-made jig, but it seems to me to cost a lot more than it orter.
On the subject of setting-up - it can be a fiddly job. I save bits of likely-looking wood to try threading, & generally have a session once a year or so. But when I get the router set up & cutting a really nice thread, I'm reluctant to un-hitch it for other jobs. That's just one of the reasons I have 3 routers, I suppose, and why there were 6 bench screws made last weekend......

Actually, I have places planned for each of them

[Woodwould]

Of all the woods I have ever tried (too many to name) Apple wood is far & away the very best. It turns like butter & takes flawless threads, but is as tough as they come.

I agree, Apple is wonderful stuff for all sorts of jigs and tools.

Don't know about using metal type dies...

Note I said metal-type taps and dies. Metal threading taps and dies are, for the most part, unsuitable for wood threading until you get up into some of the coarser BSW sizes (1-1/2" x 6 TPI, 1-3/4" x 5 TPI and 2" x 4-1/2 TPI) when all of a sudden they're quite appealing. I haven't used actual metal-threading taps and dies, but taps and dies made from these sizes of BSW nuts and bolts which I modified for cutting wood threads very successfully. I tried to find single 2" BSW nuts and bolts to make my vice screws (prior to landing the Beall tools), but couldn't find them for sale anywhere in Australia in less than multi hundred dollar packs.

[Basilg]

Ian

I would like to make up a jig to do some wood threads both large and small. I would much appreciate any details you have (photo's, sketches etc) of the router jigs you mention in this thread, If you are able to provide.

Regards

[IanW]

Ian

I would like to make up a jig to do some wood threads both large and small. I would much appreciate any details you have (photo's, sketches etc) of the router jigs you mention in this thread, If you are able to provide.

Regards

Hi Basilg - I'm not ignoring you - just a bit flat-out at the moment. Somewhere in the dark corners of my computer I think I have a pdf which is a tutotial on woodthreading - it has a few sketches & instructions on making the jig. I will see if I can find it & post it. In the meantime, there is a bit of a how-to in this thread from some time ago, it might be enough for you to get started?

http://www.woodworkforums.ubeaut.com...reading+router

Cheers,

[Basilg]

Ian

Don't burst a boiler as I am not in a tearing hurry, but your cooperation is much appreciated.

Regards