San Francisco ? A federal judge declined Friday to block the sale of remnants from the atomic bomb dropped over Hiroshima.

U.S. District Judge Susan Illston freed Butterfields Auctioneers to release the two arming mechanisms from the atomic bomb dropped from the Enola Gay on Aug. 6, 1945, killing about 140,000 Japanese.

The parts were taken from the plane by Morris Jeppson, an Enola Gay crew member who put them up for auction Tuesday. They were sold to a San Diego man for $167,500.

The Justice Department had claimed prior to the auction that the internal configuration of the thumb-sized plugs one of which was used to activate the real bomb and the other a spare was classified.

The mechanisms work similar to the pin on a grenade and resemble large cigarette lighters in a car.

Illston noted that the government asked her to block the sale hours before the auction despite not taking any action to try to obtain the devices in 1994, when they were offered for display at the government-run Smithsonian Institution.

“I don’t think you’ve made any showing, literally coming in here at the last moment. There is not a national security issue involved,” Illston said from the bench.

On Tuesday, Justice Department attorney Jocelyn Burton told Illston the devices were classified. But on Friday she said the government was not sure and wanted a bomb specialist to examine them. Illston rejected that request.

Clay Perkins, a physicist turned developer who bought the two devices, said they had great personal and historic value. He said Friday he was going to display the artifacts at his San Diego home.

Perkins said the bomb inspired him to become a physicist in his youth and said it was impossible that somebody could develop an atomic bomb by examining the devices.

“If anybody thinks that’s a state secret, they don’t understand science and electricity very well,” he said outside the courtroom.