Ah ha! That may explain it then. Mine are definitely stainless steel and very heavy! I have had no evidence of cracking. I am thinking then that this issue that Killclimbz was telling me about may be the result of them switching to alluminum ones if they have but I don`t think any of the slider plates are made of aluminium; it`s too soft of a metal to hold up to the pins. I believe stainless steel is non magnetic so you cant rely on that. I would be surprised if they did switch to aluminium really. Check the weight, I am thinking you will agree that they are too heavy to be made of aluminium.
my volie kit is over five years old and my plates are alum. There are a couple people that will weld a ride or a bentmetal with a aluminum baseplate to the volie plate. cant weld stainless to Alum.
any way, id look for a ride binding to put on the volie plates they are the lightest binding with a metal base to it. Plastic bindings flex a lot more than designed on a volie plate as the outside edges are unsupported.
shoot me a message if you have questions about building a diy splitter i've done more than 10 now and have figured out some good tricks.