Manually forming a lot of M12 threads.

[Gareth0123]

Manually forming a lot of M12 threads.

I have a project which over the next 9 months requires me to form approximately 500 or 600 M12 X1.75 threads X 20mm on 2 metres long 12Ø MS round bar.

I do not have a lathe (or free access to one), and this job is for us and friends and therefore does not warrant being contracted out, so it is all down to me: it is several hundred modular garden and tree branch supports for our gardens, 4 shared Allotments, shared 4 acre smallholding and now a shared 7 acre mixed fruit orchard we have just recently taken on. 'er-in'doors, and two friends do a bit of freelance garden design together and will probably end up wanting to sell a few of these supports like they did last year.

So without a lathe, but having a general light fabrication workshop the job is going to be a manual one for me with the 2 metre long bars laid horizontally in my trusty ancient Fortis vice.

1) How do I guarantee square to the bar M12 X 1.75 thread cutting each and every time with just a die and handle when the bar is held horizontally?

2) Is there a mains/cordless threading tool that takes M12 dies like the 1”+BSP pipe thread cutters I often see on sites and which I have myself used in the dim & distant... ... ... I could very possibly justify purchasing one.

3) Is there a tool, jig or a wotsit I could make to do this job easily?

 

[gaz_moose]

can you not just use threaded bar for your project?

to keep it square could you weld some tube with the correct ID to your die holder.

 

[rtbcomp]

Could you use tube instead of bar & fit threaded bar/set screws/bolts in the ends?

 

[Gareth0123]

No, threaded bar is far too expensive and really not suitable for the job as there are other bits welded onto the rods.............. I am only connecting bars together using M12 BZP connector nuts, hence only forming a 20mm thread length on each bar

 

[Gareth0123]

Could you use tube instead of bar & fit threaded bar/set screws/bolts in the ends?

We tried 5/8 X 16g ERW tube with M12 threaded rod welded in the ends for this job a couple of years ago.

1) Too time consuming with the extra processes involved and the threaded bar making the ERW version about 4 times more expensive to make.
2) The ERW version was no where near as strong as 12Ø MS round bar.
30 Welding the other bits on made of 12Ø MS round bar and 10Ø MS round bar weakened the ERW at the welds.
3) Corrosion from the inside out was a real issue with the ERW.
4) Wind, weather, handling and accidentally caused bent 12Ø MS round bar is very easy to straighten, the ERW versions were not, and over half were scrapped in the first year of usage because of damage.

 

[Robotstar5]

Could you get dies to fit one of these?
https://ez-tools.eu/ELECTRIC-THREADER-MACHINE-BSPT-1/2-3/4-1-1-1/4?gclid=CM2dgvWQwtQCFVXnGwodkFMATw

 

[Gareth0123]

Could you get dies to fit one of these?
https://ez-tools.eu/ELECTRIC-THREADER-MACHINE-BSPT-1/2-3/4-1-1-1/4?gclid=CM2dgvWQwtQCFVXnGwodkFMATw

Is there a mains/cordless threading tool that takes M12 dies like the 1”+BSP pipe thread cutters I often see on sites and which I have myself used in the dim & distant... ... ... I could very possibly justify purchasing one.


A friend has rung just a few minutes ago offering me his old and now unused one of them for peanuts/ a good drink/ future favours, etc. It would be great if I could either get an adaptor or an M12 die to fit it.

 

[waddycall]

Why not use the 1/2" BSP die and connect your bars together with 1/2" BSP sockets?

 

[Gareth0123]

There's a big difference between M12 X 1.75 and 1/2" BSP...... around 7mm......... 1/2" BSP is approx. 19mm

 

[Seadog]

However, 1/4 BSP is 0.518, so maybe you'd get away with that in view it being a taper thread.

 

[Gareth0123]

However, 1/4 BSP is 0.518, so maybe you'd get away with that in view it being a taper thread.

Yes, that is correct, but you can't get 1/4"BSP dies for the pipe threading machines, so I am back at the original point with the M12 X 1.75 dies.

 

[Seadog]

but you can't get 1/4"BSP dies for the pipe threading machines

Damn, I misread the ad

Update: http://www.ebay.co.uk/itm/Heavy-Dut...237005?hash=item487f690f8d:g:lVwAAOSwBahVQfJA

 

[cocker]

Could you make something up useing a Coventry die box ?
Plenty about at autojumbles

 

[Pete.]

2m studding is £3.50 a length delivered in packs of 5. It's crappy grade 4 but you don't specify what grade you need. How much you paying for steel bar? If it's hot rolled it'll probably tear up your threading dies.

 

[Gareth0123]

For 12Ø MS round bar I am currently paying £3.00+VAT which equals £3.60 for a 6 metre length or 60p per metre all in, and that is cut into 2 metre lengths (£1.20 each) for me ready to collect or delivered free when their driver comes my way (3 or 4 times a week).

I only need a 20mm length of M12 X 1.75 thread on one end of each bar, and the bars do have other bits welded to them which are made from bent sections of 12Ø and 10Ø MS round bar.

 

[Rocketman]

Really depends if you think £2.90 is worth not having to cut the bar and put thread on each end.

 

[rikrobson]

I'd be looking at an adaptor to hold the die, rather like a tailstock die holder with a shank to fit you drill. If you do it slowly it should go on ok and its only 20mm of thread.
If you fixed the drill to the bench and made a V channel to sit the bar in, concentric to the drill. You'd probably need a clamp of some sorts.

 

[500e]

http://uk.rs-online.com/web/p/produ...|prd|2052306&gclid=CN30sqzzwtQCFcIK0wod3ncB9g

 

[Gareth0123]

Really depends if you think £2.90 is worth not having to cut the bar and put thread on each end.

The threaded bar bends too easily in the wind; especially where you have welded bits onto it........... these are 2 metre long vertically placed general gardening, and fruit tree supports. With one end stuck 300-400mm in the ground and the top end supporting a fruit laden branch which will move about a bit in the wind.

Here is the original version of what they are, but the version we are now working to has interchangeable heads (M12 X 1.75) for supporting branches, netting or vine cords, etc. We also want them to be compatible with the ground pins used in our "Sideways GrowBag system: again M12 X 1.75 threads (see bottom photo on page 8 of the attached PDF document).

And I would also like them to be compatible with my "Tater Tower" (Potato box) project.

 

[Rocketman]

OK see what you are saying. Interesting utilisation of the side ways.