Any metallurgists out there? Disc brake material

[annie]

The disc brakes on my boat trailer are obsolete and have seen better days. Instead of changing hubs/stubs/calipers etc $2500 nzd I was thinking of machining off the old rotors completely (cast Iron) and having new rotors cut with a water jet, and bolt them on to the appropriately machined hub.
The disc thickness would be 1/2" and my question is.... Would Stainless steel (316/304) be suitable to handle the heat?
I see stainless disc rotors are available from manufacturers but when you get into the specs they call it an alloy bronze?
I have had a quote to cut these @ $500 nzd but not to sure if stainless will warp or work-harden with the heat?
Any thoughts would be much appreciated.

 

[OldSkool]

A few questions.
Will there be a balance issue when you attach the new rotors?
Will the old hubs withstand the added stress of SS rotors and hardware?
Cast iron is used to dissipate the heat quickly and evenly will SS act the same way?
If you upgrade the brakes are you creating any collateral issues that may arise from the upgrade?

I know the price to replace the original is high but if it has worked in the past......

 

[annie]

Thanks for your reply OldSkool,

Good questions of which I don't have all the answers.
I'll get the hubs machined leaving a centralizing flange for the rotor. Then I'll get the O.D of the rotor skimmed. This should take care of any imbalance.
The hubs do look like #$@% but these things are so massive and over-engineered I've worked out good edge margins without compromising the hubs strength.
The remaining discs are only 5/16" thick they have been machined so many times. I'm sure I've seen them red hot on occasions and have put this down to being so thin the heat build up is instantaneous.
Believe it or not the brakes still work really well. Well apart from the fact I've been through a complete set of pads in about 2000 miles!
I have seen manufactured bolt on rotors that are held on with 4 bolts @ 1/2". I was boing to use 6 @ 1/2".
I don't know how marine grade stainless will respond to heat. If it is heated and cooled evenly it should be ok?
I know they rock race cars once they have stopped to stop the pads welding and distorting the discs. I'm going to look pretty stupid if I have to do that at the truck stops! LOL
Thanks for your thoughts.
Cheers Mike.

 

[Henry Boyd]

Mike,

Are you sure the hub and rotor aren't two pieces? I can understand cast iron rotors, but a cast iron hub strikes me as odd (cast steel certainly) because of the inherent brittleness of cast iron.

Henry

 

[annie]

Mike,

Are you sure the hub and rotor aren't two pieces? I can understand cast iron rotors, but a cast iron hub strikes me as odd (cast steel certainly) because of the inherent brittleness of cast iron.

Henry

Hi Henry, I'm positive its one piece. That might explain the hubs size. It seems huge compared to modern steel type hubs.