Federal employes who think they are overworked, underpaid and pensioned off poorly have never been treated to the flip chart and statistical slide show put on by Donald J. Devine.

He is the head of the Office of Personnel Management. OPM is the civil service watchdog agency that some wags are now calling the OPD (for Office of Personnel Dismemberment).

Devine took his charts to Capitol Hill yesterday to urge that the Senate Finance Committee give speedy approval to the bipartisan plan to put all federal/postal employes under Social Security beginning next year.

At the same time Devine, who is President Reagan's caretaker of the civil service, put in a plug for the administration proposal that would force federal employes to work 10 years longer, and pay more for the same benefits they can receive today if they retire at age 55 with 30 years service.

Here is some of the data Devine presented to the Senate yesterday (and to a group of federal executives in Miami Tuesday):

* Half of all federal employes retire before age 60, compared with only 7 percent who do so in the private sector.

* Federal employes retiring at age 55 with 30 years service get an annuity equal to 56 percent of salary, whereas nonfederal workers who retire at that time get pensions equal to about 25 percent of their preretirement pay.

* Sixty percent of American workers are not covered by any pension plan other than Social Security, which pays benefits that are much less generous than the civil service retirement program.

* While data collected by government workers shows that federal pay is 18 percent behind the private sector, U.S. rates are nearly 1 percent higher when matched against industry and state-local government rates, and 11 percent higher than industry on an occupation-by-occupation matchup.

Many people--government workers, members of Congress and union leaders--disagree. They think that Devine only uses numbers and data that jibe with his conservative philosophy about government.

But like it or not, he is presenting his data to an audience that counts: new legislators (or veterans who have gotten the religion of economy) who want a quick fix to "save" Social Security and who are hearing from folks back home who think bureaucratic Washington is afloat on a sea of gravy.

White-collar federal workers are an easy target. Up until the Carter years they could usually depend on a relatively benign Congress to protect them. This permitted (or encouraged) the workers to avoid anything more militant than an occasional lunchtime protest.

It now looks as if new feds are heading for Social Security and, if Congress buys Devine's figures, a new, economy-size retirement system, too.

American Society of Access Professionals will have its luncheon meeting March 3 at Dominique's. Cecelia Wirtz assistant general counsel of the OMB as the speaker. Call Carl Coleman at 472-7453.

Best of the Engineers: The National Society of Professional Engineers will give out its engineer of the year awards this evening at its Andrews Air Force Base dinner. Federal winners are: Marvin E. Jensen, Roger L. Tuomi and Charles H. McElroy, from Agriculture; Nelson N. Hus, Bureau of Standards; Allen Lim, Air Force; Ernest K. Schrader, Alex Van Praag III, Howard E. Burnette Jr., and Norman J. Berg, Army; Thomas E. Bechert, Defense Communications Agency.

Also, Peter A. Karpovich, Deh Bin Chan, Francis E. Baker Jr., and Richard L. Britton, Navy; Henry L. Longest II, EPA; John A. Fleming, GSA; Lewis V. Wade, Chin Ted Yang, Denis P. Galvin and James P. Bennett, Interior.

Also, Peter M. Turcic, Mine Safety-Health Administration; Aaron Cohen, Space Agency; Cdr. John C. Maxham, Coast Guard; Walter Podolny Jr., Federal Highway Administration; Oscar Orringer, Research and Special Programs Administration; Frank P. Achorn, Tennessee Valley Authority and Elwin R. Paulus, VA.