Entering production in 1963 as the Mk 57, the bomb was designed to be dropped from high-speed tactical aircraft. It had a streamlined casing to withstand supersonic flight. It was 3 m (9 ft 10 in) long, with a diameter of about 37.5 cm (14.75 in). Basic weight was approximately 227 kilograms (500 lbs).
Some versions of the B57 were equipped with a parachute retarder (a 3.8 m/12.5 ft diameter nylon/kevlar ribbon parachute) to slow the weapon's descent, allowing the aircraft to escape the blast (or to allow the weapon to survive impact with the ground in laydown mode) at altitudes as low as 15 m (50 ft). Various fuzing modes were available, including a hydrostatic fuze for use as a depth charge for anti-submarine use.
The B57 was produced in six versions (mods) with explosive yields ranging from 5 to 20 kilotons. Mod 0 was 5 kT, Mod 1 and Mod 2 were 10 kT, Mod 3 and Mod 4 were 15 KT, and Mod 5 was 20 kT. The depth bomb version for the U.S. Navy was 10 kT.
The B57 used the Tsetse primary design for its core design, shared with several other mid- and late-1950s designs.