Meek and Ozgur (1991) analyzes the torque required to strengthen a fixture (bolt or mandrel) as a function of the fixture's plating method (cadmium and wax, heat treating, and phosphate and oil, denoted CW, HT, and PO, respectively).
data(torque)
A data frame with 60 rows and 3 variables:
the response, the torque required to tighten the fixture.
the type of fixture, bolt or mandrel.
the plating treatment, CW, HT, or PO.
torqueslgf