Edit: Thinking about it real quick while studying for a midterm. I'm not sure if I'd be more worried about the force exerted from the pad creating a bending stress on the caliper bracket or the torque/moment acting on the bracket due to the clamping force and the dive of the car. Either way, I think 1018 should be fine as I'd assume it should be pretty thick.
C'mon Samy, let the old dynamic systems T/A help you out: Assume Kevin's car weighs 5000lbs (that is a lot of slugs), peak decel of 1g, and the rear brakes contribute nothing... just to make you metric kids happy we will round that off to 2300kg. The bracket doesn't care about dive... Let's assume Kevin's tires are 26" diameter. Torque = I * Alpha. alpha = 1g/13". What is the average lever arm of the brake pad... man, I am making this too easy for you. Now pin the face of the bracket to the spindle and load all that geometry into your favorite FEA package and safety factor > 10... I would guess 1018 at that thickness would be extreme overkill. Post your assumptions and your FEA output plot and I will grade it later.
Michael
1968 Barracuda Notchback Coupe
440 EFI 6-pack, T56 Magnum 6-spd
