Required Allowable Contact Stress Number

$9\mathrm{.}55.$

Compute the required allowable contact stress number, $\backslash (\backslash$mathrm$\{$s$\}\_\{\backslash$mathrm$\{$ac$\}\}\backslash ),$ using Equation $(9-31).$ Use a service factor, SF$,$ of $1\mathrm{.}00$ unless stated otherwise.

Then specify suitable material for the pinion and the gear based on pitting resistance. Use steel unless an earlier decision has been made to use another material. Then evaluate whether the earlier decision is still valid. If not, specify a different material according to the most severe requirement. If no suitable material can be found, consider redesigning the original gears to enable reasonable materials to be used.

Use the data and results from Problems $37,43$ and $49.$