Thread box

[HUON]

Can anyone tell me where I can buy a 1 1/2" and a 2" thread box? I want to make threaded wood screws for a tail vise and bench vise. I've got the smaller versions, purchased from Carba-tec, but they can't help me with the larger sizes.
Cheers.

[IanW]

Huon, you have a number of choices. One option is to get yourself a Beall threader. They only go up to 1 1/2", and to be honest, I don't think they got it right, there are too many tpi on their tap.

These 'traditional' tap & die sets suffer from the same too-fine thread and in addition, you can run into quite serious trouble threading most of our hard woods with a threadbox. There are only a few woods that I've found that thread reasonably well with a threadbox, and about the only commercial species is Vic. Ash (& you need to select your stock carefully). Most of our hardwoods come out looking more like the horror examples shown here, because they take the edge off even hard cutters pretty quickly.

I also don't like the design of either of the taps in the kits mentioned above, because they don't have much of a 'pilot' shaft, which means they will be difficult to keep straight when tapping. It takes a good bit of power to drive a large metal tap through hard wood, and it's very easy to cut a wonky thread if you aren't very careful. A long pilot keeps the tap straight in the hole you're tapping.

If you have a friend with a suitable (large!) metal lathe, you could get them to make you a tap. This one was made for me by a friend. There is no need to harden wood taps, unless you intend to tap thousands of nuts. This one was turned from soft steel and still works well after tapping many nuts (it takes two people to drive it!): 2 inch tap end2.jpg

I've recently become a convert to the good old low-tech type of wood tap that's been around for centuries. The only machinery you need is a wood lathe (which you will want anyway, if you are going to become a serious wood threader), you can easily make a tap, any size you want, in any tpi you choose. This is a very simple, low-tech device, and once you are able to make a good nut, you can make your own simple router jig for threading screws. This 2", 3tpi was made with such a setup: Bench screw.jpg Takes a bit more time to tap a nut because you have to do it in multiple passes, but from go to whoa takes all of about 10 minutes, so it's hardly a big deal. In some ways it's easier to do than with the all-metal taps.

I've just written an article for AWR showing how to make the tap & jig. I guess it wouldn't be proper to pre-empt it here, the first part will be in the next issue (September), so if you can wait a few weeks, there will be some detailed instructions available. Once it's out, I'm happy to take questions.....

[HUON]

Thanks for the good advice Ian, I'm looking forward to the September issue. It's a good mag, AWR, I think I've got as many AWR magazines as I have Wooden Boat magazines.

[IanW]

Here you go, Huon - a little teaser from AWR for the forthcoming issue.
Dunno who the old coot in the video is.......

Cheers,

[Sawdust Maker]

standing at the letterbox patiently waiting, waiting

[IanW]

standing at the letterbox patiently waiting, waiting

I hope you are wearing a warm coat & someone is supplying you with food, Nick! The mag. hits the news-stands towards the end of Sept, I believe......

[HUON]

Thanks Ian for the video, really looking forward to your article.
Cheers
Brendan

[HUON]

Got the mag today, look forward to a strong cuppa coffee tomorrow morning and mag in hand.

[HUON]

Like the paper template idea, looking forward to the next instalment

[IanW]

....Like the paper template idea ......

Thanks, H. That was the only original bit from me, the way the bloke did it in the article where I first saw this type of tap had a rather cumbersome way of laying out the driver kerf. As long as you get the diameter of the tap right, and the correct slant (don't get it back to front like I did the first time, unless you really want a left hand thread! ), the template method works a treat...

Cheers,

[markharrison]

Well I can tell you where to buy new ones, but stand by for serious sticker shock: Wood Thread Cutting Tool | FINE TOOLS
999 Euros for the 2 inch version. That is $1471.61!

[Bushmiller]

IanW's article in "AWR" over two issues is starting to look like exceptional value!

Regards
Paul

[IanW]

Ouch! Yes, a couple of issues of AWR won't set you back quite that much....

And take note of the fine print: "When possible, use only dense and fine-grained woods - beech, cherry and pear, for example. Woods such as pine and oak are unsuitable. Soaking the wood to be threaded in oil for two days makes it more pliable and reduces the risk of tear-out of the raised threads. "

Equivalent woods to those mentioned aren't easy to come by in Oz., but there are some that should work pretty well with the old style dies, such as Myrtle Beech, perhaps. The kits mentioned have 2 cutters, which ought to make them last a lot longer & do a neat job.

It's just so much easier with a $25 carbide bit and a no-cost jig for your router....!

I'm still uncertain about oil treatment of the wood to be threaded. It seems to help quite a bit when tapping some woods, not much with others, and with router threading, it's more of a nuisance than anything because the oily sawdust tends to clump & clog things...

Cheers,

[jmk89]

If you can't wait for the next issue of AWR, Richard Starr wrote an article that deals with a similar technique in Fine Woodworking - issue number 6 (1977). Copies are available in many Australian libraries, if you don't have the DVD for all copies from 1975 -2015.

[IanW]

If you can't wait for the next issue of AWR, Richard Starr wrote an article that deals with a similar technique in Fine Woodworking - issue number 6 (1977). Copies are available in many Australian libraries, if you don't have the DVD for all copies from 1975 -2015.

That's the article that got me started, Jeremy. 'Twas a while back, alright!

There are multiple ways to de-frock the moggie. I did a bit of a search and came up with several ways that are different (but goodness me, some people like to make tiresomely long videos - I got seasick watching one of them!).

There's this method, which has potential.....

And if you don't own a router, you can make screws with your drill-press! This jig uses essentially the same principle as the one that will be expounded on in part II, but he uses a half-nut to pull the screw past the cutter, which makes initial setup a little easier, perhaps.

That was just a quick look, I know of at least one other way to cut screw threads. So if you can't wait for the next issue, find the Starr article, or do some internet searching. The screw-cutting jig is simple, and if you are lucky like I was, it might work first time...

Cheers,