# Forum Home Renovation Metalwork & Welding  Thread cutting?

## paddyjoy

Hi guys, 
I'm a complete noob when it comes to metal working. Is it a big job to cut threads into solid M12 rod if you have the skills/equipment? Is this within the capabilities of most "metal fabricators"? 
Thanks

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## ringtail

One can do anything with the right gear. What are you trying to achieve ? More than one way to skin a cat

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## paddyjoy

> One can do anything with the right gear. What are you trying to achieve ? More than one way to skin a cat

  Thanks, it's for a stairs balustrade, I need to have 34 solid M12 rods threaded on both ends. The steel rod is cheap but I'm wondering if it would be an expensive exercise to get them threaded?

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## ringtail

You could pick up a tap and die set and give it a go. Mild steel rod is pretty soft so it should cut ok. Paying someone to machine threads on a lathe would no doubt be more expensive but an awful lot quicker. Maybe give a machine shop a call for a quote.

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## paddyjoy

> You could pick up a tap and die set and give it a go. Mild steel rod is pretty soft so it should cut ok. Paying someone to machine threads on a lathe would no doubt be more expensive but an awful lot quicker. Maybe give a machine shop a call for a quote.

  Watching some youtube videos it doesn't look too hard (famous last words...)

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## Bros

Get bright steel if you want to thread it as it is exact size and can easily be threaded.

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## intertd6

A few years back I had to thread 100 ends of M20 gal rod for 125mm in length with a manual die, after that M12 would seem doable for anybody.
inter

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## paddyjoy

> Get bright steel if you want to thread it as it is exact size and can easily be threaded.

   Thanks for the tip, any issue powder coating bright steel as compared to mild steel?   

> A few years back I had to thread 100 ends of M20 gal rod for 125mm in length with a manual die, after that M12 would seem doable for anybody.
> inter

   :Eek:  how long did that take?

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## Marc

Bright rod, a decent vice and beware of the lure of tap and die set. 
The hardware grade or Aldi grade are absolutely terrible. A good quality set is bound to cost good money... 
Go to total tool or similar joint and buy a good quality m12 die and it's corresponding wrench, die holder, handle or whatever they call them here.  
Make sure you grind an even chamfer at 45 around the edge of the rod for the die to start cutting. Some die are split to adjust to cut to tight or loose thread using the screws in the wrench and the grub in the die. If you get an adjustable that does not have it's own screw, make sure the screw in the wrench is sharp enough to wedge inside the split or the split will close as you turn and you will get a very loose thread.  
Use a bit of oil to lubricate, make sure to start the thread with the die square to the rod,  and go 1/4 turn back when the go gets tight. Take it easy and you will do just fine.

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## Bros

> Thanks for the tip, any issue powder coating bright steel as compared to mild steel?
> ?

   Bright steel is exactly the same as mild steel it is just the way it is finished. Ordinary mild steel is hot rolled and is slightly oversize and has the mill scale coating I think bright is cold rolled but it will cost a bit more than mild steel bar.

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## PlatypusGardens

> I need to have 34 solid M12 rods threaded on both ends

  Good grief.  :Shock:  
You're gonna have sore shoulders after that....
I'd get a couple of quotes first. 
Sometimes the time, frustration and effort you save by handing over a bit of cash is well worth it.   :Wink:

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## Uncle Bob

If it can be thread all the way along, you could get some lengths of AllThread Macsim M12 x 1.2M Hot Dipped Galvanised Threaded Rod | Bunnings Warehouse

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## Marc

What? I missed that ...34 rods ... 68 threads ... Where is your nearest engineering shop? 
You use a manual die to cut a few threads, not 64... well i do anyway.

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## PlatypusGardens

> What? 34 rods ... 68 threads ... Where is your nearest engineering shop?

  Eggsacktly. 
Taking in to account that this is apparently his first attempt at thread cutting, there will be a few whoopsies (I still stuff up about every 3rd time haha) so probably more like 75 threads and a few rods in the bin. 
Also, if it's for something that's to be seen = balustrade = has to look good, you need to secure the rod when cutting without leaving any marks and so on. 
The engineering shop will put it in a machine, get them straight, square, level, neat, tidy and the same length every time all day long.    :Smilie:

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## Marc

Not to mention the broken die and even broken wrench if you buy cheap ones.

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## PlatypusGardens

> Not to mention the broken die and even broken wrench if you buy cheap ones.

  
Good point.
Compare prices of local engineering shop vs a decent cutting die

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## Marc

I believe Paddyjoy is in the north side of Sydney. Try a search in the Blacktown area, there should be a dozen of turner shops there.

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## phild01

What about threaded rod and run it through an outer tube.

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## GeoffW1

> What about threaded rod and run it through an outer tube.

  That is a good idea. Choice of materials then on the tube. 
Cheers

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## David.Elliott

> What about threaded rod and run it through an outer tube.

  *+1 Phil, I LIKE that idea...*

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## Marc

Without more information we can't suggest alternatives. Of course there are multiple alternatives. Balusters made out of powder coated 12mm rods sounds like a very specific requirement. My guess, a repair or an existing or well under way project. The OP will need to say if he wants to change it just because of one or two hundred dollars in turning fees.

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## paddyjoy

Thanks everyone I will try and get some quotes, hard at this time of year however if I can get some to do this for a few hundred dollars there is no way I would attempt it myself. 
Phil that is an awesome idea however won't help me in this case as I need the rods to be 12mm solid (engineering requirement) and it don't want the overall width to be anymore than 12mm. 
For anyone that is interested this is for a suspended stairs, powder coated rods will be going through one side of stair threads, other side of threads attached to wall. It has been fully engineered but it's up to me to determine the best way to implement it.

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## Marc

Interesting, I take that the handrail holds the threads, how is the handrail supported?
I suppose that the balusters will need to be different lengths if you have more than one per thread.
I would use high tensile nuts.

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## paddyjoy

> Interesting, I take that the handrail holds the threads, how is the handrail supported?
> I suppose that the balusters will need to be different lengths if you have more than one per thread.
> I would use high tensile nuts.

  Yes each rod is a different length and will be bolted through a PFC directly above. Handrail will have to go on wall. It will be a bit like picture below.

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## Marc

how does the rod hang from the PFC at an angle? Do you need to bend the rod? Or is the PFC horizontal?

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## paddyjoy

> how does the rod hang from the PFC at an angle? Do you need to bend the rod? Or is the PFC horizontal?

  PFC is horizontal so they will come straight through the bottom flange and be bolted on top side.

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## PlatypusGardens

> What about threaded rod and run it through an outer tube.

  That's all good and well if you can get tube that is the exact same ID of the OD of the threaded rod.
AND get them all cut the same length withing a mm so they don't rattle.

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## Bros

I like to think I am not to bad with a lathe and it would take me three cuts and each cut would be nearly 5 Min so it would be expensive. I can only agree with tha other posters to get some 316 stainless tube cut to the exact length to slide over some threaded rod. To stop it moving just fill the tube up with Sikaflex or for more expensive use epoxy glue. Using 316 tube will remove the need for powder coating.
.

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## Marc

> PFC is horizontal so they will come straight through the bottom flange and be bolted on top side.

   Yes, makes sense. Is the channel exposed ... that is can you see the thread and the nuts?

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## paddyjoy

Ok so I got a quote today and it's like $6 a thread, pretty reasonable!

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## paddyjoy

> Yes, makes sense. Is the channel exposed ... that is can you see the thread and the nuts?

  PFC will be completely hidden in between the floors however I will have a strip of powder coated steel which the rods will pass through before they go into the PFC. This strip will be positioned inline with the ground floor ceiling and will be there purely for anesthetic value. Not sure if that makes sense, will have to post a photo later!

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## PlatypusGardens

> Ok so I got a quote today and it's like $6 a thread, pretty reasonable!

  
Do it

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## Marc

Well ... it's twice what I thought but probably not much in the price of the project. 
may be you can get a better price ?

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## Bros

Is that 68 times $6 or 34 times $6?

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## PlatypusGardens

Well... 
I would probably pay $408 to have that done and spend two days doing something useful rather than faffing around with a thread die.  
But yeh, maybe get another quote or two anyway.    :Smilie:

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## PlatypusGardens

> Is that 68 times $6 or 34 times $6?

  
34 rods threaded both ends = 64x6=$408

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## Bros

> 34 rods threaded both ends = 64x6=$408

   Just clarifying the price as he may be thinking per rod. $408 would be a reasonable price as it would take 30 min per rod if they were being cut in a lathe but much quicker using a screwing machine.

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## PlatypusGardens

> Ok so I got a quote today and it's like *$6 a thread,*

   

> I need to have *34 solid M12 rods threaded on both ends.*

   

> Is that 68 times $6 or 34 times $6?

     :Unsure:  
I'd draw a picture but I really can't be bothered.....  
Being a smartarrse takes little to no effort, however.   :Wink:

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## PlatypusGardens

I probably have better things to do right now anyway.....  
Off I go

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## Bros

> I'd draw a picture but I really can't be bothered.....  
> Being a smartarrse takes little to no effort, however.

  I know it's hot but maybe a sit down in the Air Conditioning will fix you up.

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## paddyjoy

Ha ha! It's $5.25 for the short thread (30mm - bottom) and $6.45 for the long thread (120mm - top) + gst, total would be $437, I'm happy to pay that considering most people are closed at this time of year and it would cost me way more in time and tools to do it.

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## PlatypusGardens

> sit down in the Air Conditioning

   :Nonono:

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## intertd6

> Thanks for the tip, any issue powder coating bright steel as compared to mild steel?    how long did that take?

  the first couple were about half an hour each, the bars were 6m long so they had to be done horizontally, it was hard work, after that I welded a M20 nut to a winch drum drive shaft, cut two turns on the bar by hand then threaded it into the nut, then as the shaft & bar rotated I just held the die handles as the thread cut at the supported other end, after 100mm of cutting the die was smoking the cutting fluid. After 4 or 5 cuts the handles were starting to get warm at the ends.
inter

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## PlatypusGardens

> the first couple were about half an hour each, the bars were 6m long so they had to be done horizontally, it was hard work, after that I welded a M20 nut to a winch drum drive shaft, cut two turns on the bar by hand then threaded it into the nut, then as the shaft & bar rotated I just held the die handles as the thread cut at the supported other end, after 100mm of cutting the die was smoking the cutting fluid. After 4 or 5 cuts the handles were starting to get warm at the ends.
> inter

  Wow

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## Marc

If I had to do that, I would have found it the perfect excuse to buy a lathe ...  :Smilie:

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## paddyjoy

Rods are back from the engineering shop  :2thumbsup:

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## PlatypusGardens

That's some pretty long threads!   :Shock:

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## paddyjoy

> That's some pretty long threads!

  Ha ha yes since I was getting these done professionally I decided to leave lots of contingency. The threads on the top are 120mm long. This will allow me to make small adjustments to the height of the threads and also allow me to recover if I completely botch the drilling int the steel beam.

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## PlatypusGardens

What did it cost in the end?

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## MetalWorkerSafe

Hi, 
I know it is a bit late posting given the job as been completed but was it mentioned (I didn't bother reading all the replies) by anyone that the holes could have been drilled centrally into the round bars and then tapped out to suit the screws that would lock the bars in place on the wooden step? 
Just a thought :Rolleyes:

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## paddyjoy

> What did it cost in the end?

  Sorry platy just noticed this, total job cost me $890, threading was $411 the rest was for the supply and delivery of the bar.   

> Hi, 
> I know it is a bit late posting given the job as been completed but was it mentioned (I didn't bother reading all the replies) by anyone that the holes could have been drilled centrally into the round bars and then tapped out to suit the screws that would lock the bars in place on the wooden step? 
> Just a thought

  Thanks yes I did think about this but the reason I didn't do this was because I would then have a fixing into the side of the stair tread that would be visible  :Biggrin:

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