Screw cutting wood screws?

[BrokenBiker]

Been asked if i can make a stainless or aluminium (probably stainless) mount for some solar lights to drop into...pretty simple design, bit of 30mm round bar with a 20mm hole drilled through the diameter at a slight forward angle, but they want it to screw into a fence post and have requested it be 1 piece, even after I explained it would be easier for the machining to make a plate to take a wood screw, then thread the mount onto the plate...or even recess the back of the mount and weld a wood screw to the back...

They are worried about the screw corroding for some reason...

So, are there any readily available form tools for the wood screw thread form? I'm limited to 8tpi so that limits me to the size of usable screw i can cut, in fact I doubt I will find a tool so much that I haven't even measured the pitch I would need to cut yet...

I could grind something, obviously, but they don't know that and if a tool isnt available, its an excuse not to do it...or atleast, do it my way

 

[Pete.]

Tell them to buy stainless screws

 

[indykid]

Weld a stainless coach screw to the back of it and turn the weld back. Bore a socket for the parallel section for fixturing.

If they can come up with design criteria like that, they'll never know the difference.

 

[BrokenBiker]

Tell them to buy stainless screws

I have...thats where the small recession and weld the screw on idea came from, but they are still insisten on it being made from 1 piece...

I've tried 3 of 4 different designs that would make more sense but obviously the people that cant make it themselves know better...

I'm on the verge of telling them its not possible at this point

 

[indykid]

I have...thats where the small recession and weld the screw on idea came from, but they are still insisten on it being made from 1 piece...

I've tried 3 of 4 different designs that would make more sense but obviously the people that cant make it themselves know better...

I'm on the verge of telling them its not possible at this point

Tell them it needs thread whirling and you'll need to bill them for the equipment.

Even paying for the extra length of 30mm stainless bar to turn the screw from would make it a complete non starter in my mind.

 

[BrokenBiker]

Tell them it needs thread whirling and you'll need to bill them for the equipment.

Even paying for the extra length of 30mm stainless bar to turn the screw from would make it a complete non starter in my mind.

That settles it...not doing it...they can either have a screw welded on or they can find someone else

 

[Ton-up]

or silver soldered on.

 

[Agroshield]

It is possible to buy studs that have a coach screw (wood) thread one end and a metric thread the other. Seen an domestic environment holding your washbasin to the wall. They might be a hlafway house and only need a female thread tapping into the bar.

If the holder has to be oriented in a certain clock position (i.e. it has an 'up' and a 'down') sell them on the difficulty of achieving this with a one piece item - it will go tight at three o'clock, so like the grand old Duke of York, it will be neither up nor down.

 

[BrokenBiker]

told them their idea isnt feasible and they either let me do it my way or i dont do it...havent heard back since...not the end of the world, they are the type to pick holes in everything and are never forthcoming with any sort of payment...hard enough to convince them to buy the stainless when they saw the price of it

 

[rtcosic]

You haven't told us how many they want.

Big difference in suggestions between half a dozen and half a million.

I'm guessing they want half a dozen priced at tuppence a tonne delivered.

 

[BrokenBiker]

You haven't told us how many they want.

Big difference in suggestions between half a dozen and half a million.

I'm guessing they want half a dozen priced at tuppence a tonne delivered.

They wanted 15 and if their usual antics are anything to go by it would have been for free

 

[Johnnybravo]

They wanted 15 and if their usual antics are anything to go by it would have been for free

There are easier ways to go bankrupt…tell them to take a hike

 

[MattF]

they are the type to pick holes in everything and are never forthcoming with any sort of payment...

Why even humour them in the first place? Those are not the type of people to do work for.

 

[BrokenBiker]

Why even humour them in the first place? Those are not the type of people to do work for.

To keep the peace...until we settle my grandmother's estate, we cant cut them off...their time is coming

 

[Kram]

If not too late my suggestion are these - does the fixing even need to be threaded? If it doesnt require frequent removal.

Drill, say, 10mm hole, and turn the bar to dead on 10mm, or even 10.05mm, it will take a few taps to go in. Wood likes to swell when it gets wet so likely it will be held firm for a very long time.

Another option is a tapered square point like a file tang, quite easy to mill in lathe. Heat it up near red and tap it in, wont be coming out any time soon. Pre drill the hole about 3-4mm and the tang to be 4- 7mm. The heat will firstly char the surface wood in the hole and make it rot resistant while the steam will allow the fibres to flex and make it a perfect tight fit.

 

[Agroshield]

Another option is a tapered square point...

The small challenge to consider with that is it does not have any rotational adjustment so the item might not end up level.

 

[indykid]

They wanted 15 and if their usual antics are anything to go by it would have been for free

15?!

Even if you were given the material, that's a pee pee take. Don't tell them you can't do it how they want it, tell them you just can't do it.

Their time might be coming but your time will be long gone, wasted making these ridiculous things.