Woodthread tap and die set

[David N]

I am looking to purchase a 5/8th woodthread tap and die set. Does anyone have one for sale?

[MrPete]

Hi David, you can just use a regular tap and die set in wood far as I know. You don't specifically need a "wood" one.

Out of curiosity I checked Hafcos website for a 5/8th set.

http://www.machineryhouse.com.au/T838 and http://www.machineryhouse.com.au/T944 appear to be the two that you will want.

What are you making?

[David N]

Hi David, you can just use a regular tap and die set in wood far as I know. You don't specifically need a "wood" one.

Out of curiosity I checked Hafcos website for a 5/8th set.

http://www.machineryhouse.com.au/T838 and http://www.machineryhouse.com.au/T944 appear to be the two that you will want.

What are you making?

I have to turn a 5/8th thread on an end of a shaft which is a component of an old organ that I'm helping to restore. This thread that I'm copying has 7 tpi, which appears to be common from around the 1850's to the 1900's.

[steamingbill]

Hello,

Depending upon diameters and thread type I think it could be relatively easy for somebody who owns an imperial metal lathe to cut a 7tpi thread in a piece of wood for you. Any metal lathes near your place ?

Does 5/8 mean the external diameter of the screw required is 5/8" ?

Am a newbie at this and may be talking rubbish - Will have a go in shed tomorrow - may need to modify cutter clearance angles - dont know - interesting.


Bill

[Prle77]

Carbatec sells them

[IanW]

Carbatec sells them

Yes, but not 5/8". In fact that's a size you might not find anywhere, these days. Dies for metal don't do a very good job on most woods, though the taps work well in side-grain, and produce very nice threads in hard, fine-grained woods. In any case, a 5/8th metal die will be way too fine at 11 tpi (Whitworth or NC).

If you have the time & the patience, one solution would be to get someone to make you a tap (taps for wood can be made from mild steel, and are not terribly challenging for someone with metal-lathe skills), then use that to make a die-box for a router to cut the male thread you need.

I have a tap I made from the guts of an old brass water tap. It is 5/8" diameter and at 8tpi, very close to what you need, but not close enough if you have to match existing nuts, unfortunately.

Cheers,

[steamingbill]

Had a go at cutting 7tpi on a piece of wood dowel on the metal lathe.

Although it worked fine on a test piece of plastic, it didnt work well in the wood. Probably because the wood fibres are running lengthways and the way the metal lathe is set up the cutting bit tended to rip the fibres out of the side of the wooden cylinder rather than shear through them. Maybe if I sharpen the bit a lot better it would work. Also speed was relatively low compared to a spindle on a wood lathe.

If you cant find the right thing to purchase then perhaps somebody who knows a bit more about woodturning and metal turning could set up a cutting tool so that you could cut clean sharp 7tpi wooden threads using the metal lathe screwcutting functions.

Bill

[David N]

It appears that the 5/8th inch thread was a common used size back in the 1900's? Cant understand why 5/8th is not used now as it appears a practicable thread size for timber. 1/2 inch is too small and the next size 3/4 inch too big.

[IanW]

It appears that the 5/8th inch thread was a common used size back in the 1900's? Cant understand why 5/8th is not used now as it appears a practicable thread size for timber. 1/2 inch is too small and the next size 3/4 inch too big.

Indeed, 5/8" is quite a handy size, David, & I don't know why it isn't still popular. While 1/2" is getting a bit thin, it can still make useful threads, you just have to be particular about the woods you choose for making smaller screws. And I disagree entirely that 3/4 is too big - maybe for what you have in mind, but I find it is ideal for workaday hand-screws with jaws of around 10 inches long. That's about the most useful size for me (they open to around 200mm).

Here are 3 sizes of clamps using 3/4", 5/8" and 1/2" threads. Clamps various sizes.jpg

I use the 3/4 size the most, but the 1/2" screws get plenty of use, too. You just have to be careful not to try tightening them with the jaws off-parallel, as it is vey easy to snap the bottom (compression) screw if you do. (That applies to all wooden handscrews, btw, even large sizes like 1"...DAMHIK!). The 5/8 clamps are a very useful size, too, but I tend not to use these because the thread is really too fine (these are made using the tap I made from from a tap mentioned above. They take sufficiently longer to open & close that I tend to reach for coarser threaded clamps in preference, but there is no questioning their clamping abilities. Now that I have my own little lathe, I mean to make myself a decent 5/8th tap, one of these days when I get the necessary round tuit..

And just to be completely ridiculous, I have a 3/8th 6 tpi tap which I've used to make tiny thumbscrews. Now that is getting a wee bit fragile, but if made from a suitable wood, they seem to work ok....