Document 9JMZen67XOQvzVb9j5V50voe3

Friction Identification System for Brake Linings and Brake Blocks for Motor Vehicles - SAE J866a SAE Recommended Practice Report ofBrake Committee approved March 1964 and last revised September 1966. Editorial change May 1967. Scope-This SAE Recommended practice is intended to provide a uniform means ofidentification which may be used to describe the initial friction characteristics ofbrake linings and brake blocks for use on motor vehicles. NOTE: It is emphasized that this recommendedpractice does not establishfriction requirementsfor brake linings or brake blocks,, nor does it designate other significant characteristics ofbrake linings or brake blocks which must also be considered in overall brake performance. The basis for determining the friction coefficients for brake linings and brake blocks are tests in accordance with SAEJ661. Coding - The code will consist oftwo letters reflecting the friction coefficients as follows: Code Letter C D E F G H Z Coefficient ofFriction Not over 0.15 Over 0.15 but not over 0.25 Over 0.25 but not over 0.35 Over 0.35 but not over 0.45 Over 0.45 but not over 0.55 Over 0.55 Underclassified The first letter will represent normal friction coefficient and the second letter will represent hot friction coefficient Normal Friction Coefficient-Normal friction coeffi cient is defines as the average of4 points on the second fade curve, located at 200,250,300, and 400 F. Hot Friction Coefficient - Hot friction coefficient is defined as the average of 10 points located at 400 and 300 F on the first recovery; 450,500,550,600, and 650 F on the second fade; and 500,400 and 300 F on the second recovery. NOTE: Ifany temperature point or points required to calculatefriction coefficients are not reached in the prescribed time limit, the coefficient offriction value at 10 minutes shall be used to give thefull number ofpoints' required. EXAMPLE: A lining having a normalfriction coeffi cient of0.29 and a hotfriction coefficient of0.40 would be coded "EF ". Location ofCode - The appropriate code designation will be marked on an external contacting surface in letters not less than 0.125 in. in height. MAR 22 RECO OCfSfc. X. FRICTION ' PRODUCTS EL P. O. Box 3250, Winchester, Virginia 22604 N0V016415