Thread: Brakes
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Old 05-28-2010, 04:58 PM   #57
Chris_B
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Join Date: Apr 2010
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Quote:
Originally Posted by Scooby921 View Post
For the most part one set of rotors isn't going to last longer than another. They are all made from cast iron. Durability is a property of the material, not the name of the manufacturer. The big difference is the quality put into manufacturing the rotor.
It would be nice and easy if this were true, but it certainly is not. There are a lot of choices when selecting gray irons for rotor castings, such as G1800, G2500, G3000, G3500, and so on. Some even use high-strength ductile iron, but that does give different friction and abrasion resistance properties. Even within the variants, there are very wide alloy and impurities tolerances that can be tweaked to give better results.

Most of the stuff coming out of Taiwan and China (and probably India as well) are made from G2500 or G3000 at best. Well, OK, they SAY it is. Some of their U.S. distributors don't really know or haven't checked. The trouble is that there is "good" iron (with less impurities) and "bad iron" (more impurities). You are correct that within any one specification, you can pour either good or bad iron. It depends a lot on how the melting occurs, the tooling process, the plant procedures and a ton of other stuff.

Quote:
Originally Posted by Scooby921 View Post
One way you can save on cost is to buy standard non-slotted or drilled rotors. When they wear down or you build up pad deposits its usually $10-20 at your local autoparts store to have them turned down and you can reuse them (usually once).
Slotted and/or drilled rotors can be turned if done with care, but I have found it is better to use higher quality rotors that survive 2-3 pads sets. I do scrub them with a Flex-Hone or Scotch-Brite when changing pads to remove the old transfer layer. Some pad compound are highly incompatible with others and cause trouble if mixed. Turning is a last resort as it lightens the rotor, removing some heat capacity.
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