coefficient friction between alloy mg and anodized alloy?

[woocash]

Hello, everyone! I do not write often on this forum, but more and more times I have found several solutions to technical issues not always banal. This time I find myself in front of a seemingly trivial problem at first sight, but I can't come up with it. I have a project of a nut and the calculation of his torque. This is a single nut system for automotive racing applications (formula sae). the big problem that I match is the calculation of the torque tightening, or rather not the calculation in itself but the finding of data for the calculation itself. I found, on the manuals, that for the calculation of the torque of any nut, it always makes reference between the friction between the threads and that between the head of the nut and the piece. to calculate them, however, of course, you need to know the friction coefficient between the two materials. and here comes the beautiful!
in my system I have in play a circle in magnesium az91d (design vehicle) and hard anodized aluminum for the nut (from sae regulation) and consequently also for the hub-wheel.

That's the problem I find myself: what is the friction between magnesium (in general) and anodized aluminum? Do any of you have any data about this?

 

[meccanicamg]

I have no data but you can take a sloping plan of one of the two materials and put a piece of the material upside down. when it starts slipping, mix the angle and through the tangent you get the friction coefficient of first detachment. if you are looking for formulas both on the network and on the forum. sample 10 tests and calculate the average. the method is reliable.

 

[Matteo]

Spinous soil... I proceed so usually: I look for a relatively reliable value and then I do the calculation by taking a 20% or 20% below looking, according to the formula/simulation, to put me in the most unfavorable conditions.