Both disc rotors and brake pads are manufactured to exacting tolerances so why bed them in?
Regardless of material chemistry, the two mating brake components made from Iron and friction compounds must engage at a molecular level to cause the resistance that we know as friction.
This mechanical engagement may be generated by means of adhesion or abrasion depending on the brake pad material type.
The adhesion method requires the brake pad to evenly deposit a transfer layer onto the disc rotor.
The transfer layer bonds to the iron surface during the bed in process with heat and pressure.
The brake pad then clings onto the transfer layer generating frictional resistance.
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