Apex to back, in a bevel gear or hypoid gear, is the distance in the direction of the axis from the apex of the pitch cone to a locating surface at the back of the blank.
Salary DOE means that the salary depends on experience of the candidate. A similar term is DOQ which means salary depends on qualification. Be careful with DOE job offers with small companies where they only can fill one position. Every position ...
The dollars-and-cents value of a CISSP certification is hotly debated. The Simply Hired website, for example, shows that the average U.S. salary for all of their job listings that contain the term cissp is $80,000. PayScale.com shows salaries for CISSPers from $60,000 to $160,000 -- quite a spread.