The Expanded and Annotated My Life and Work

MATERIAL SELECTION AND DESIGN 
FOR RELIABILITY (DFR)
The book introduced these concepts earlier, and the next section expands 
on the need to select materials for the jobs they are to perform, e.g., tensile 
strength, elastic performance, and resistance to wear. The best material for 
one application is unlikely to be the best for another, which was a consid-
eration that Ford’s contemporaries apparently overlooked.
The following segment introduced the concept of design for reliability 
(DFR) decades before it became a recognized science. Ford recognized 
that a product is no more reliable than its least reliable vital component, 
and that any failure of said component could make the product unusable 
or even endanger the owner’s life. This ties in with modern reliability engi-
neering, and also failure mode effects analysis (FMEA).
* * *
Having vanadium in hand I pulled apart our models and tested in detail to 
determine what kind of steel was best for every part—whether we wanted a 
hard steel, a tough steel, or an elastic steel. We, for the first time I think, in the 
history of any large construction, determined scientifically the exact quality 
of the steel. As a result we then selected twenty different types of steel for the 
various steel parts. About ten of these were vanadium. Vanadium was used 
wherever strength and lightness were required. Of course they are not all the 
same kind of vanadium steel. The other elements vary according to whether 
the part is to stand hard wear or whether it needs spring—in short, according 
to what it needs. Before these experiments I believe that not more than four 
different grades of steel had ever been used in automobile construction. By 
further experimenting, especially in the direction of heat treating, we have 
been able still further to increase the strength of the steel and therefore to 
reduce the weight of the car. In 1910 the French Department of Commerce 
and Industry took one of our steering spindle connecting rod yokes—select-
ing it as a vital unit—and tried it against a similar part from what they 
considered the best French car, and in every test our steel proved the stronger.

---

50  •  The Expanded and Annotated My Life and Work
The vanadium steel disposed of much of the weight. The other requisites of 
a universal car I had already worked out and many of them were in practice. 
The design had to balance. Men die because a part gives out. Machines wreck 
themselves because some parts are weaker than others. Therefore, a part of 
the problem in designing a universal car was to have as nearly as possible all