Fixed bolt head 1

[edward995]

My client request a hexagon bolt with the length up to 1 to 2 meter. Currently I am doing this with welding a nut on it. The clamp load is acceptable but welding did take lot of time and some water flow out from the head after galvanizing.


I have found a solution from alfa lava company, any idea how to do this method. Have tried using stamping but result nut cracking

https://www.youtube.com/watch?v=ndDK9vAckSE&t=18s

 

[TugboatEng]

With the information you have provided, Loctite is still the ideal solution. Incorrect application would explain your poor performance. Are you using the correct primers/activators? Large diameter threads have large clearance and require different formulae because of that. 263 is rated on a 10mm thread.

http://tds.henkel.com/tds5/Studio/S...at=MTR&subformat=REAC&language=EN&plant=WERCS

 

[3DDave]

Data sheet says Loctite 263 is 60% as strong at 150C as at 20C, still returning to 75% at 20C after long exposure.

Typical reason for failure is insufficient cure time and use on non-ferrous surfaces without using the activator. It takes a long time to cure on stainless and aluminum. I took an aluminum bronze insert threaded into aluminum out after a week and the loctite was still wet (no activator, just like the factory did; doing trouble shooting.)

Loctite 648 might be a workable choice. It's a shaft locking compound that gets stronger with heat aging. ≥25 N/mm² should be enough. I think 60 degree threads double the surface area vs the nominal pitch diameter cylinder.

https://www.henkel-adhesives.com/us/en/product/retaining-compounds/loctite_648.html

 

[edward995]

Thanks for the advice, will try loctite and center punch. its for long term project, gonna figure out which is more cost effective and time saving.

 

[badservo]

If I understand correctly, you have a rod that is only threaded at each end and you want to fix a nut to one end so it functions like a bolt instead of a threaded stud.
I would also try the proper Loctite and primer/activator first, but what about castellated nuts?
[URL unfurl="true"]https://www.mcmaster.com/nuts/locknuts/metric-medium-strength-steel-locknuts-for-use-with-cotter-pins-class-8/[/url]
But you say welding took to long so drilling a hole may be even worse.

How about a clamping collar with threaded bore?
[URL unfurl="true"]https://www.globalindustrial.com/p/one-piece-threaded-clamping-collar-recessed-screw-climax-tc-025-28[/url]
Should be fast.

None of that addresses the "The clamp load is acceptable but...some water flow out from the head after galvanizing", can you explain more?

 

[SnTMan]

Suppose you just used a self-lock nut on one end and free-running nut on the other?

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[TugboatEng]

Deformed thread nuts are a pain to install on a rod because you'll need to double nut one end to run it on and then remove the double nuts to install. Loctite with a long enough thread engagement can exceed the torsional strength of the fastener.

The only reasons not to use Loctite are temperature and chemical compatibility and neither seem to be an issue for OP.

 

[edward995]

Yes, this is high temperature application, using astm a193 b7 stud and 2H nut.

 

[mfgenggear]

I don't have that spec. What is the temp?

 

[edward995]

150 - 180 Celsius

 

[TugboatEng]

Check out Loctite 2047. It maintains 60% of maximum strength indefinitely at 180C and is for large diameter fasteners. I am not an expert on the product line so I do recommend contacting the manufacturer to clarify the best option but they certainly have products that will work.

http://tds.henkel.com/tds5/Studio/S...at=MTR&subformat=REAC&language=EN&plant=WERCS

 

[mfgenggear]

Yes ultra strength ultra high temperature 650 deg. F