Proposal for an SAE Standard to Define, Dimension, and Measure Disc Brake Plates for Manufacture

As the brake industry moves completely into globalization, a standardized method to define and validate the dimensions of backing plates, in a way that is both clear and feasible, is of critical importance for manufacturers at all tiers. The plate drawing not only defines the component as it fits into a brake assembly; it is also what the plate supplier relies on to define the plate for manufacture. If a drawing does not define every dimensional aspect of the product with perfect clarity, in ways that are easily measured, loss of time and resources will result from questions and/or mistakes. This paper proposes an SAE standard for defining the dimensional requirements of backing plates on the drawings themselves, and defining the measuring procedures used to validate those dimensions. The proposed standard employs already established methods such as geometric dimensioning and tolerancing (GD&T), including instruction on its proper application to features specific to backing plates. Current ‘best practices’ of design and drafting in our industry are similarly highlighted; drawing clarity, revision control, and dimensioning for both function and manufacturability. Generic examples are used to illustrate both the advantages of best drafting practices, and the potential failure modes that can result from poor drafting practices. The standard also proposes the best methods of measurement required to properly validate requirements such as feature size and location, surface roughness, plate flatness and bow shape. Most importantly; this paper invites the industry professionals responsible for both creating and using backing plate drawings, to join or collaborate with the SAE Brake Linings Standards Committee and help grow this paper from a proposal to a globally accepted engineering standard.