Metalurgia Casal was the largest Portuguese motorcycle manufacturer, based in Aveiro. It was founded in 1953 and its first products included agricultural engines. Business leader João Casal met representatives of Zündapp at a trade fair in Hanover in the early 1960s, and then started to build mopeds with Zündapp engines. From 1966 he made his own engine, the Casal engine, which is a modified copy of the Zündapp, to be built in a a large number of variants. The first all-Casal model was the four speed 50 cc scooter Casal S170 Carina. Casal expanded the production to ordinary mopeds and motorcycles. The first was called K181. In the early-1970s Casal began to export their products, for example to the UK, Netherlands, Denmark and Sweden. Car production was additionally planned, but not realised. As the increased purchasing power in their home country Portugal, their most important market, slowed down the sales of mopeds, bankruptcy was a fact in February 2000. In connexion with this, unfortunately, parts of the company's archives were destroyed. Today it operates as a Suzuki representative in Portugal.
Some Casals has survived in their home country Portugal, but additionally for example in Sweden, where the Swedish type K190 is quite common with collectors.
In 1980 Jan Nijhuys took a 1/4 mile record with a Casal Sparta Plompen. Quarter mile was covered in 15,26 seconds and record speed after 402m where 94.29 km/h.
In 1981 the Dutch Jan Huberts bettered the 50cc speed record with a HuVo-Casal to 224 km/h.
To become competitive, Casal made a partnership with the Dutch company HuVo.