What is the largest nuclear weapon (in megatons) ever produced?

Question

During the Cold War, both the US and the USSR build numerous nuclear weapons, often measuring the power of those weapons in kilotons/megatons of TNT explosive power. Which country build the largest weapon, whether or not it was tested?

Answer 1

The sun, while nuclear, is NOT a weapon produced by man.

500 Megatons is also the product of an overfertile imagination and you are totally clueless to any realworld test results.

Black Sabbath is the most correct other poster so far but wikipedia is not the most reliable source (though a good starting point in researching)

The largest device ever tested is the Tsar Bomba but it was a test device only with no practical military application. THere is evidence that the actual yield of this device was 57 Megatons not 50. though it is true the original design yield was 100 Megatons.

as for actual weapons I can only find for the USA.
The Mk/B-41 was the highest yield nuclear weapon ever deployed by the US. It was also the only three-stage thermonuclear weapon ever developed by the US, and it achieved the highest yield-to-weight ratio of any US weapon design. The B-41 was deployed in a a "dirty" version (the Y1, with a U-238 encased tertiary stage) and a "clean" version (the Y2, with a lead encased tertiary stage). It may be that both used a secondary with a lead fusion tamper. There are actually two reported yields for this bomb, "less than 10 Mt" and 25 Mt. It is possible that the 25 Mt yield applies only to the dirty Y1 version, with the clean Y2 version having the lower yield.

UPDATE:
KatVic you really have no clue as to what you are talking about. a "Thermonuclear" device is any Nuclear Device that uses Fusion rather than Fission. Nearly every nuclear weapon tested since the early 50's has been a thermonuclear weapon and they have been tested in the air. in space. in the water, and below ground.
please do some actual research or at least know what you are talking about before posting.
thank you

Answer 2

The largest produced was the 100 megaton Soviet nuke in the 60s. It was tested and detonated at only 50 megatons, half of its original design. It was later deactivated, since the 500 kiloton range strategic nukes were enough to obliterate the earth.

Weapons designers now say they can build a 1000 megaton range weapon, in response to planet killing asteroids. It was felt, however, that the size of the yield, especially in the wrong hands, was more dangerous than the prospect of a planet killing asteroid. And besides, the result of blowing up an asteroid would only make larger number of hurtling rock blasting the earth rather than one big one, something that would've been worse.

Anyway, the science is there, but the rational control of limiting to smaller yields has been the order of the day.

Answer 3

Approximately 50 megatons. They wanted to build it bigger, but they were scared of spreading fallout with too large a bomb.

Answer 4

The sun

The sun hits the earth with more energy every day, than all the nuclear weapons and all the nuclear, hydroelectric, and coal power plants have put out in the last hundred years.

Answer 5

russia 500 megaton was detonaed in the 50's

Answer 6

That would be a "Thermo-Nuclear" weapon. It has never been tested above ground, only at 28,000 ft. underwater. It caused a 7.8 magnitude quake in it's aftermath. Detonated on land, They have no-idea when the chain reaction would, if ever, stop. Quite a deterrant for other nations I would say.

Answer 7

it will be produced later,but matereal's ready and its computor test already done