Material and Process Selection Charts

Introduction
The charts in this booklet summarise material properties and process attributes. Each
chart appears on a single page with a brief commentary about its use. Background and data
sources can be found in the book “Materials Selection in Mechanical Design” 3rd edition, by
M.F. Ashby (Elsevier-Butterworth Heinemann, Oxford, 2005).
The material charts map the areas of property space occupied by each material class. They
can be used in three ways:
(a) to retrieve approximate values for material properties
(b) to select materials which have prescribed property profiles
(c) to design hybrid materials.
The collection of process charts, similarly, can be used as a data source or as a selection tool.
Sequential application of several charts allows several design goals to be met simultaneously.
More advanced methods are described in the book cited above.
The best way to tackle selection problems is to work directly on the appropriate charts.
Permission is given to copy charts for this purpose. Normal copyright restrictions apply to
reproduction for other purposes.
It is not possible to give charts which plot all the possible combinations: there are too
many. Those presented here are the most commonly useful. Any other can be created easily
using the CES software*.
Cautions. The data on the charts and in the tables are approximate: they typify each class of
material (stainless steels, or polyethylenes, for instance) or processes (sand casting, or
injection molding, for example), but within each class there is considerable variation. They
are adequate for the broad comparisons required for conceptual design, and, often, for the
rough calculations of embodiment design. THEY ARE NOT APPROPRIATE FOR
DETAILED DESIGN CALCULATIONS. For these, it is essential to seek accurate data
from handbooks and the data sheets provided by material suppliers. The charts help in
narrowing the choice of candidate materials to a sensible short list, but not in providing
numbers for final accurate analysis.
Every effort has been made to ensure the accuracy of the data shown on the charts. No
guarantee can, however, be given that the data are error-free, or that new data may not
supersede those given here. The charts are an aid to creative thinking, not a source of
numerical data for precise analysis.