i might just use the ti... at least thats only one person so far that can say "i told you so" when i crash and burn!
I am no expert at all, but I would question whether it has anti-corrosive properties when assembling parts of dissimilar metals. Stainless steel into aluminium or magnesium will very quickly start corroding without some sort of inhibiter. Yes, it will lube the threads & help prevent gauling, but depending upon what this anti-sieze is made up from could cause accelerated galvanic corrosion. I do stress it "could" not that it "will", like I said I'm no expert, this is just my opinion/thoughts.
my thoughts also hence the question. hopefully i can get a definitive answer as im putting it together real soon!
Read this Chiz... http://www.nsxprime.com/forum/showt...olts-on-aluminum-parts-Any-corrosion-Problems
There won't be a definitive answer but in this instance I would listed to Mr Severe as he's not a daft lad
You can look up torque settings online, thread size, pitch and grade of bolt. Any lubrication on the thread will cause an over torque, as usually torque values are given for dry threads.
As far as I can tell this is specifically designed for dissimilar metals - cycle parts these days are made of all manner of exotic materials and this is what Shimano use to prevent a reaction. Not sure if it’s copper based or not though - couldn’t find that info.
@chizel The two lubes I use have been mentioned. The Pankl and the Wurth brake paste Andy mentioned. I may have some sachets of the Wurth stuff, if not I can sort a spoon full of Pankl stuff. Mail me your address x
I have used Ti bolts into Aluminium and Magnesium extensively during my 20 or so years in Formula 1. Rocol do an anti seize paste which is preferable as it protects better against seizing up. Corrosion was never a issue but things didn't exactly stay together for long. I would warn that if the tolerance of the hole is tight they seize. If the tread tolerance is on the tight side, they seize. By the time you feel them going a bit tight it's too late. For me they are best if used with a nut, specifically a k-nut which is coated in a lead plating which stops seizing up. They are not as strong as steel bolts. If a application with a steel bolt has a safety factor of 4 then the equivalent Ti bolt is probably still plenty strong enough. If things are a bit marginal then they aren't good enough. Stainless has similar issues. If memory serves me right a A2 stainless bolt it rated 5.5. Ordinary Steel is 8.8. AN aircraft bolts are 10.9 which gives a good compromise between tensile strength and hardness. 12.9 Steel tend to snap without warning. Pretty much all structural bolts on a formula 1 car are AN Nas bolts 10.9. they also offer a ti version but with a lower tensile strength. Believe me if Ti bolts were better, they would be used more extensively in Formula 1. They spend on average about £20000 on every Kg of weight saving by better design or exotic materials. So if you could simply change the bolts from Steel to Ti that would be a real bargain. Hope this helps a little.
I couldn't say, depends how much safety they factored into the original bolts. I personally wouldn't do it.
Well every day is a school day - went down the rabbit hole trying to understand why this is such a difficult one and found out things I didn’t learn in a Chemistry class! Found some handy charts! Turns out Titanium and Magnesium are pretty as dissimilar as it’s possible to get! Although based on the info below - pretty much any other metal will corrode Magnesium. The aim of an anti seize compound is to create a barrier between the 2 metals - often by using another metal that sits between the 2 dissimilar metals on the chart. But as you can see - Mag is so different in voltage to all of the other metals this is difficult. So if you are going to do it - then ideally you need a none metallic anti seize and never get the bike wet - in fact according to the info below it’s kind of a miracle that Magnesium doesn’t just turn to dust on contact with air...... “Whenever different metals are positioned in an electrolyte within close proximity to one another preferential corrosion becomes an important factor to be aware of. Galvanic corrosion typically attacks junction areas of dissimilar metals and occurs when the following three conditions are met. Condition 1: Metals must have a galvanic incompatibility (voltage difference - see below table). Condition 2: An electrolyte must be present (water is a good example). Condition 3: There must be an electrical conducting path between the metals. The galvanic series chart below shows metals and their electrochemical voltage range (relative activity in flowing sea water). A typical rule of thumb is that voltage differences of 0.2 Volts or more suggest a galvanic corrosion risk. Generally speaking the further apart the metals in the galvanic series the greater the risk of corrosion, with the metal being of least noble (Anodic) class typically corroding.”
Good man - you found the galvanic series/dissimilar metals charts! This is why magnesium alloys are never used in commercial aircraft - they corrode to buggery on contact with anything +electrolyte!
