Small Thread/Tapping Job

[Lappy]

Hi All,

Hope its ok to post this here i'm normally in the wood forum section as my metal skills are nil to none!

I have a small metal work job that I need done, unfortunately it may be too small as I've had a couple of quotes done by commercial shops and i think they are just pricing it out of the ball park as they don't want to do it (also going by their tone on the phone!).

Basically I'm looking to have some 5mm Stainless steel rod cut at 440mm long, M5 Right handed thread (50mm long) at one end and M5 Left handed thread (50mm long) at the other.
Also two 'round nuts' made from 10mm SS rod, Drilled and tapped, again one left handed thread and one right handed thread.

In total I'd be looking at getting 3 sets of the above done.

Can anyone recommend any small shops that may be able to do this or alternatively any forum members want to take a shot for either cash or trade of services? (have a medium CNC for wood, plastic, alluminum etc)
Can also supply technical drawings.

Thanks in advance.
Glenn

[Gavin Newman]

50 mm M5 thread in stainless is going to be challenging, especially the LH end. I'm assuming you are making a turnbuckle arrangement? What's the end use for this going to be?

My mistake - I misread the post to mean he needed an internal 5 mm thread!

[Lappy]

Hi Gavin - could probably get away with 35-40 RH and 30 on the left hand if that was to make it easier?

Its for a truss rod which goes into the guitar necks that I make, its used to bend the neck in an up or down direction as needed.

Cheers
Glenn

[Pete F]

Hi Glenn, welcome to the evil world of metal

I can't see the rod presenting too many problems, but a couple of things that would be considered by someone doing the job.

I'd probably want to use dedicated thread inserts to do stainless like that. I know they're not required in theory, but SS work hardens easily and it could present problems when taking "spring" cuts. The thread inserts aren't cheap ... and easily broken

At M5 the nuts would need to be tapped. Left hand 5 mm taps would probably need to be ordered by most anyone on the board here, and in stainless I would want to only use good quality taps. Could you substitute the SS nuts for brass?

Finally, are you intending to supply the material? What type of time frame are you thinking about?

Out of curiosity what sort of money was a commercial shop asking?

Pete

[Lappy]

Hi Pete - thanks for the reply you raise some good points

The main reason for going with stainless was that i need the pieces to last, so no corrosion or binding on the thread, the unit may need to be adjusted from time to time over years of use so if it was to bind it wouldn't be good.

I'm not really up on the types of stainless, but are there any grades that could make the job easier?

Brass would work well I think and that's a great idea, i couldn't see these being a problem, in that case i could probably do those myself due to it being a bit softer ( I also have two HSS LH & RH Taps on hand) in the drill press.

with that being said it would just be the rod that needs to be done, I do have the SS on hand and can supply to make things easier.

Time frame wise, no hurry but in the next couple of weeks would be super helpful if it was possible.

On average they wanted $150-200 for the rod and $50 per nut, unfortunately well out of my price range, but what are your thoughts? is it on the expensive side or is that about right?

Thanks
Glenn

[Steamwhisperer]

Hi Glenn,
My son keeps asking me to make these. My plan was to make up a tailstock die holder with a through bore morse taper. That way any amount of thread was possible.
As Pete says a left hand tap would need to be purchased which is no biggy.
If you aren't in a screaming great hurry for them (as I'm in the middle of a project at the moment https://www.woodworkforums.com/f65/re...d-pump-169841/) I could give them a shot.

Phil

[jack620]

Hi Lappy,
I can't see the need for a SS truss rod in a guitar. There are very old guitars getting around with mild steel truss rods. Have you experienced corrosion problems with your truss rods before?

[Pete F]

Glenn it may just be me, but the SS nuts are a concern to me when I saw what you wanted to do. I think the brass may be an easier solution.

If it were me I'd probably single point thread the LH thread and probably just cut the RH thread with a die. I was trying to imagine if I could single point an internal LH thread, but I honestly think it's too small to be anything other than a PIA. I think it would be possible to grind up a round bar, but really you're looking at a tap. Maybe if I were in the workshop I may be thinking differently, but that's how I see it at the moment. M5 gets kinda small!!

Pianos I may be able to help with, but I don't know anything about guitars, so don't know what one of these thingies is, but if all you're worried about in the threads not binding together due corrosion then you really don't need stainless. Well, unless you're planning to regularly jam under the ocean A bit of light lube really does seal out nasties remarkably well.

Pete

My plan was to make up a tailstock die holder with a through bore morse taper. That way any amount of thread was possible.

Phil, I made up a tailstock die holder but it doesn't have a through hole. However in my experience once the die is started it will keep running reasonably true, at least with the lengths I've threaded. I've probably gone as far as, I don't know, 20x OD??? Something like that anyway, and the die was still going straight. May be different for a precision screw, like a leadscrew, for example. But that's my experience with this type of thing.

[Michael G]

My concern with a S/S rod and S/S nuts would be that the two parts would gall and then they could not be moved. I'd go for brass nuts on S/S rod myself. How long are the nuts by the way?
Pity about the M5 - I have LH taps and dies for M6 and M8...

Michael

[Steamwhisperer]

Phil, I made up a tailstock die holder but it doesn't have a through hole. However in my experience once the die is started it will keep running reasonably true, at least with the lengths I've threaded. I've probably gone as far as, I don't know, 20x OD??? Something like that anyway, and the die was still going straight. May be different for a precision screw, like a leadscrew, for example. But that's my experience with this type of thing.

Hi Pete,
now I am embarrassed Of course, a through hole isn't needed. Once the die has started straight it will cut straight.
Glad your out there Pete, I need someone to keep me from being a complete dill

Phil

[Steamwhisperer]

Doesn't brass and stainless corrode when in contact with each other??

Phil

[Lappy]

Thanks Guys,

I have been using this style of truss rod STEWMAC.COM : 4mm Allen Nut Hot Rod Truss Rod which is SS and i've never had an issue. Most commercially made truss rods now days are made from SS.

The main reason for changing this type of rod is it is too thick and you have to remove to much timber from the neck to install it, weakening the neck.

I have had guitars in for repairs for truss rods that have either binded or snapped off at the nut and they are a real PITA to fix! its a lot of effort to remove and reinstall a rod, normally starting with steaming off the fret board etc etc.

As i offer my guitars with a limited lifetime warranty i just wanted to cover my bases and remove any possibilities of binding. But if its too hard to do it with stainless then i might just have to use mild.

Thanks for everyone's input and guidance
Cheers
Glenn

[Lappy]

Michael - sorry bit slow to hit send on my msg just saw your post, they will be 8 mm

As most have suggested i think doing them out of brass will be the go, i should be able to make these up myself being a softer material.

Cheers
Glenn

[RayG]

Hi Glen,

They look like standard barrel nuts, have you tried the fastener suppliers? (the Left hand thread might throw a few of them for a loop.. )

Regards
Ray

[Lappy]

Hi Ray - Yes they sure do (my old man said the same when he saw them!) unfortunately the smallest i could find was M6 internal thread and no luck with left handed threads

Cheers
Glenn