Brake Pad Materials

[TeeBee]

I was looking for some new brake pads and came across the info below it saves a lot of hearsay and C*** it was new info for me so I thought I would share it.


"All DOT approved pads have friction codes a.k.a edge codes that would help one to understand their performance characteristics. This would help us all understand how pads are baselined, rather than having to rely solely on variables and "opinions" of other users. Lets call them cold bite and warm bite (friction or torque).

The scale is E-H, with E representing no or little friction or bite in comparison to H, with more bite or higher coefficient of friction.


Some cut/paste info:

This two letter edge code mandated by the DOT, and painted on all street legal brake pads, will give you some indication of their ability to bite and resist fade, because of the wide range involved in each letter, it is only a rough indication.
Explanation of D.O.T. Edge Codes Located on all Brake Pads Official D.O.T. Edge Code Coefficient of Friction (C.F.)
@ 250 F and @ 600 F Comments
EE 0.25 to 0.35 both temps 0-25% fade at 600 F possible
EF 0.25 to 0.35 @ 250 F 0.35 to 0.45 @ 600 F 2% to 44% fade at 600 F possible
FF 0.35 to 0.45 both temps 0-22% fade at 600 F possible
GG 0.45 to 0.55 Very Rare
HH 0.55 to 0.65 Carbon/Carbon only. O.K. up to 3000 F where it glows

Notes: These edge codes are located on the edge of the friction material of every brake pad by government regulation, along with some other codes. The first letter is a grading of the C.F. at 250 F and the second letter is a grading of the material at 600 F. Each letter grade can actually have quite a range of C.F. But a difference in the letter grade from medium to hot temperature could be an indicator of fade. The letters can be in any order. Therefore FE pads fade when hot, and EF pads would not grab when cold.. Also, you should know that Steel on Steel has a C.F. of 0.25!! (I just looked up steel friction coefficients online appears to be .6 - but whatever) So EE pads have only marginally more torque than no pads at all! Therefore FF pads are usually considered the minimum for a high-performance pad.

I also noted in online research that "European" pads are usually F-H rated, probably why they give that great braking performance at the expense of dust.

Most popular street pads I can find info on are EE rated..but it's hard to find this information as oddly it's not widely distributed - though required by DOT to be on the pad."