AB - Preface - Preface to the First Review

During the years 1977-1980 the FEMFM quality manuals for friction materials appeared and they were welcomed as a long overdue and generally accepted specification by all those concerned, suppliers as well as customers.

These quality manuals described the characteristic features known at that time and their admissible limits as they had been accepted with the mainly asbestos materials even accounting for the qualitative demands from the customer side.

In the meantime materials have undergone changes, the formulations containing asbestos have been replaced by those free of asbestos, but the demands made on the quality of the products increased considerably as well. Instead of the approach to things formerly determined by AQL (Acceptable Quality Level) it is today the "Zero Defect Philosophy". This requires a review of the manuals in order to be able to use them once again as a recognized quality standard.

The description of the characteristic features and their design was defined anew while technological processes, especially safety aspects and the demands made by the brake, clutch and automobile industry were given careful consideration.

The AQL values have been dropped and a substitute of admissible and inadmissible characteristic features is presented as a replacement.

The current volumes one to seven have been replaced by a Cataloque of Characteristic Features.

A glossary of technical terms is available separately.

The present edition represents the current status of the attributive description of friction linings. We are convinced that it will prove to be a suitable assessment system for practical use, just like the previous versions.