Kroil is great with any stuck bolt.

Not sure if it will damage paint though.

Is the fastener stripped? The torque required to break away the galvanic corrosion shouldn't be that much, but bad corrosion could impact the ability of the fastener to hold torque.

What is the location and material combination?

I am thinking of going to all stainless on the front of the bike for this reason. I already replaced all of the fasteners on my XLab with stainless. They old nuts and bolts were rusted beyond recognition. The bolts on my aero bars are pretty must ruined.

Use a heat gun to expand the female threads along with pentrating oil, and put your allen key in the icebox.
Then put he frozen allen key into the bolt and give it a mighty good torque.

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The best solution for this is Park Tools Anti-Seize Compound (ASC-1). Unfortunately for you, it has to be applied before the corrosion has taken place...

Be careful using stainless fasteners on load bearing parts. in general they are not as strong as the black ones. It's often better to take preventative measures again corrosion when installing new bolts: anti-seize on threads and something to act as a corrosion inhibitor on the exterior.

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Developing aero, fit and other fun stuff at Red is Faster

What's the purpose of the frozen Allen key ?

WD :-)

It's to cool the hex bolt it will be stuck into and make it contract. In my experience it's not useful as there's just too little ability for the hex key to store heat due to its very low specific heat and the limit to how cold a freezer will cool it. We use to do something similar with seized spark plugs in aircraft cylinders years ago, It involved discharging a CO2 fire extinguisher into a cone formed around the spark plug. It really cooled the heck out of the spark plug and would often help break it loose.

Hugh

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Genetics load the gun, lifestyle pulls the trigger.

Thanks for your response :-)

I thought it would be something along those lines and whilst the theory is good, I couldn't see it working 'practically' on a bike sized bolt with such a small contact patch between hex key and bolt head for it to work.

I wondered if the poster had actually had any success in applying that process :-)

WD :-)

Screw I was having problems with was the seat post clamp on a 2015 S5. Bought a crank-based PM with shorter cranks, so really need to raise the seat a bit. Was able to get it freed up on Saturday afternoon. It had been in place about a 18-months and was covered with white powdery mineral deposits. I cheated, and stopped by the LBS at the end of my Saturday ride, and the mechanic there put a mighty-big allen on it and got it moving. It popped and cracked for about the first three revolutions. Sounded like something was cracking apart, but when we got it all out and cleaned up, things looked very normal.

Screw went back in with a lot of anti-seize.

Lesson learned for me. I'm going to have all my exposed bolts on a periodic PM program to try and intervene before they get so bad.

To humor the populous...
This statement is true for - basically - all bolts. Alloy steel (in this case with black anodize coating) is the strongest material choice; over Ti, Stainless, Magnesium, Delren/thermoplastic/nylon (obviously).

Sure, to humor the pedants, it's possible to buy a low grade alloy steel bolt which doesn't have the strength of Ti/Stainless.

Given the torques on most bolts - say 4-8Nm - the bolts shouldn't be pushed to their limits. Although, who knows what bolts are being used. It seems somewhat unlikely they're using 180ksi fasteners.

I agree :-)

I wouldn't hesitate to use stainless or Ti anywhere on the bike (and do so).

What really surprised me is that some of the bolts that's came with my torpedo kit were 12.9's ... WTF ? lol

WD :-)

That's a hell of a metaphor, if used properly

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"What's your claim?" - Ben Gravy
"Your best work is the work you're excited about" - Rick Rubin

Ha Ha, that's one way to look at it!

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