ONE DAY, in the early part of May, Gordon Bradley went out to mow his lawn in Burke, Va. Bradley is the coach of the Washington Diplomats, the city's soccer team, and, as we all know, coaches are busy people.

Bradley was in a hurry to finish cutting the grass. His machine was not. He had experienced some problems with it before. This time, the drive chain came off. Bradley took a stick and tried to wrangle the chain back in place. The stick slipped. Bradley's hand fell into the spinning blades.

"My hand was a mess," said Bradley afterwards. He spent more than three hours on an operating table at George Washington University Hospital, where doctors attempted to make some order of his mangled limb. Several bones were fractured, some tendons torn, muscles and nerves damaged throughout. His thumb and middle finger had to be sewn back on.

Lawn mowers are designed to cut grass, not human flesh. But, as Bradley found, they can do an equally good job on either. Each year several thousand Americans test on themselves the cutting power of a lawn mower blade that can revolve at speeds of 200 miles per hour. The Consumer Product Safety Commission (CPSC) continues to report about 60,000 mower-related hospital emergency room injuries.Of the 47,000 linked to power walk-behind models last year, about 30,000 resulted from either a hand or a foot coming in contact with the blaed.

Some slip and their foot ends up under the mower. A surprising number lose fingers trying to dislodge clogs, or adjust the wheels, while the mower is still running. Many of those hurt are children less than 13 years of age. The total cost of these mishaps, authorities estimate, is in the neighborhood of $300 million.

For several years now, the CPSC has been trying to develop a safety standard for lawn mowers. In 1973, the Outdoor Power Equipment Institute (OPEI), the industry trade association, petitioned the CPSC to draw up a mandatory standard. The commission thought the OPEI's suggested standard inadequate and asked Consumers Union, the publishers of Consumer Reports magazine, to draw one up instead.

Finally, in February of this year, the commission issued its standard. Suits were immediately filed against it. Manufacturers sued in the U.S. Fifth Circuit Court in New Orleans. They say the standard prescribes mower design, rather than how the mower must perform.

The standard, which lists Dec. 31, 1981, as the ultimate compliance date, requires that feet that do slip under the mower be unable to touch the blade and that the blade stop turning automatically three seconds after the owner has released the handle. The standard does not address the hazard of objects propelled at high speeds by the mower blade.

"We feel that they're straitjacketing us," said Dennis Dix, OPEI executive director. The OPEI has been working with the commission staff on possible alternatives to the standard and hopes to present an amendment this summer that would allow more leeway in mower design.

David McLaughlin, board chairman of the Toro Company, says that although it supports the suit and an amendment, Toro is proceeding with product alternations in accordance with the new standard. He expects such devices as a "deadman clutch," that would stop the blade while the motor is running, or possibly automatic engine shut-off and electric starters, will add about $35 to the cost of the average lawn mower.

Honda is expected to have such a mower on the market this summer at prices ranging from $349- $449.

If you can't wait till 1981 to mow the yard, consider using the mower you have wisely. Sandals, for instance, may keep your feet cool, and you may like the way grass tickles the bottoms of your bare feet. But you will find a lawn mower a poor pedicurist. Wear sturdy shoes with non-slip soles.

Fill the tank all the way when you start. Refilling while the engine is hot can cause a nasty fire or explosion.

Try to gather up junior's baseball bat and other toys, and any loose boulders, before mowing.

Wet lawns are slippery and tend to clog the mower. If you must remove grass from the underside, turn the mower off and disconnect the spark plug.

Some safety features to look for on new mowers are a deflector that directs discharge downward, when the grass catcher is not in use; a shield in the rear to keep feet from under the mower; and an exhaust pipe that is on the opposite side of the mower from the discharge chute.

If at all possible, ask the kid next door to mow the lawn for you. That should make both of you happy.