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 Joao Casal met at a trade fair in Hanover in the early 60th century, representatives of Zündapp and then started to build mopeds with Zündapp engines. From 1966 he made an own engine, the Casal engine, which is a modified copy of the Zündapp, witch was to be built in a variety of variations. First own 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 70th century Casal began to export their products, for example to UK, Netherlands, Denmark and Sweden. Car-production was also planned, but not realised. But as the increased purchasing power in their home country Portugal, which of course was the most important market, slowed down the sales of mopeds and the bankruptcy was a fact in February 2000. In connection with this, unfortunately, parts of the archive was destroyed. Today it operates as a Suzuki representative in Portugal.
Some Casals has survived in home-country Portugal, but also for example in Sweden, where the swedish type, K190, is quite common by collectors.