More than 8,000 U.S. officials begin a totally different career ball game this week. It intentionally strips away much of the protective insulation the so-called supergraders have used to sometimes frustrate, block or change political orders from on high.

Volunteers for the new SES (Senior Executive Service) have been promised substantial pay raises, Congress willing. They also will get the chance to earn five-figure bonuses, get more time off and take more exciting - and less secure - assignments than fellow bureaucrats at the $47,-500 career pay pinacle.

The SES arrives officially Friday. It is the cornerstone of President Carter's reform of government. Idea is to make people who run the federal establishment more responsive, permit special rewards for those who respond well, and removal for those who do not.

Those who meet the test - they will be graded by peers and political bosses - will move up in rank, honor and pay. Those who do not can be eased back into the more easy-going civil service, retired, or if necessary fired much easier than at present.

Virtually all of the SES members live and work in metro Washington. Nearly all of them are in Grades 16, 17 or 18, which now, because of a pay freeze, all pay the same $47,500 salary. That may or may not go up 5.5 percent, if Congress allows executives to get raises scheduled for rank-and-file civil servants this October.

(Fearing that Congress will maintain the $47,5000 executive pay lid for political reasons, administration sources are quietly working to exempt SES members from any pay freeze).

People going into the SES have been offered one of six new rank and pay levels. They are:

Executive Schedule 1 - $44,75

Executive Schedule 2 - $46-470

Executive Schedule 3 - $48,250

Executive Schedule 4 - $50,100

Executive Schedule 5 - $51,450

Executive Schedule 6 - $52,800

Most people going into the SES will be placed, initially, in the ES 4 pay and grade level. All career members of the SES will be eligible for bonuses of up to $20,000 per year, although rules say only a handful can get the payments, which range down to $5,000 each year.

Future executives joining the upper reaches of government, and those promoted will have to go into the SES. Typically those entering the SES today will be eligible for retirement in 5 to 9 years. In a relatively short time the current crop of converted-supergraders, products of the old system, will be gone or ready to leave.

Each year up to 5 percent of the SES career people can be given the title "Meritorious Executive." In addition to the honor, they also will get a $10,000 bonus. Those named "Distinguished Executives" (1 percent of the SES career work force) will get $20,000 bonuses.

Later this week the office of Personnel Management will have final figures expected to show that 99 percent of the supergraders eligible for the SES volunteered for it. That's an impressive figure, but not all that suprising. Top administration officials have made it clear that people eligible for the SES who stay out of it can all but forget about promotions or better assignments.

OPM brass also are trying to arrange a symbolic White House ceremony, perhaps next week, with the president giving a Ross Garden pep talk to some new SES members.