German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-641 had a displacement of 769t when at the surface and 871t while submerged. She had a total length of 67.1m (220.1feet), a pressure hull length of 50.5m (165.7feet), a beam of 6.2m (20.3feet), a height of 9.6m (31.5feet), and a draught of 4.74m (15.55feet). The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of NaNPS for use while surfaced, two BBC GG UB 720/8 double-acting electric motors producing a total of 750PS for use while submerged. She had two shafts and two 1.23abbr=onNaNabbr=on propellers. The boat was capable of operating at depths of up to .
The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . U-641 was fitted with five 53.30NaN0 torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.82NaN2 SK C/35 naval gun, 220 rounds, and one twin 2sp=usNaNsp=us C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.
The boat's short service career began on 24 September 1942 for training with 5th U-boat Flotilla, followed by active service on 1 March 1943 as part of the 7th U-boat Flotilla. It ended ten months later when she was sunk in the North Atlantic.
In four patrols she sank no ships.
U-641 took part in thirteen wolfpacks, namely:
U-641 was sunk on 19 January 1944 in the North Atlantic in position 50.4167°N -67°W; depth charged by Royal Navy corvette . There were no survivors.