Zinc plating bolts.
Turbo Mini Forums

I have been taking appart some callipers, I will need to get some new bolts for the S callipers but the bolts in the metro ones should do fine, they just that the look a bit bad/rusty.

I am preparing (quite) a few parts for zinc plating and am considering adding the bolts that keep both calliper sides together (not the ones that fix to hub).
However I read there is a risk of Hydrogen embrittlement when plating high tensile bolts.
(also when searching on TM: )

I can always buy new bolts but adding the ones I have to the plating batch costs nothing exta.

I am planning to consult the plater but was wondering what experiences are here at TM?

Dazed and Confused....

8.8 grade or equiv imperial grade will be Ok. 10.9 grade will require 8-10 hrs at 200 deg C with in 1 hour of plating. 12.9 grade will need 24 hrs. This is should give you a fighting chance. Most OEM not longer use embrittling finishes in any safety critical applications such as braking systems due to the risk associated with the finish.

Edited by shellspeed on 17th Mar, 2013.

A bit more info now I'm sat at work with the data:

8.8 grade - S grade 51-60 T/in² or 240-300Hv

10.9 grade - V-X grade 65-75 T/in² or 320-380Hv

12.9 grade - W grade80-88 T/in² or 385-435Hv

S, V, X and W will be on the head if present same as 8.8 etc. There is a thread that explains the dash markings somewhere on here as well but the same principle applies.

Perfect bit of info there, much appreciated!

I have just ordered new bolts for the four pots and S calipers.
Already plated and much cheaper then getting them from MS.

Thanks again,
Han

Dazed and Confused....