Giannini Cobra Series Phosphor Bronze 6 String Acoustic Guitar Strings .010-.047

These Giannini acoustic guitar strings are Phosphor Bronze wound with a hexagonal tinned steel core. Tone is a little brighter than 85/15 strings due to the use of the Phosphor in the alloy. These have a bright tone without being too excessive. 

The Cobra series presents all the versatility of Giannini strings. The strings for acoustic guitar Giannini Cobra GEEFLEF are coated with Phosphor Bronze, suitable for musicians who like a richer sound.

Phosphor Bronze

Formed in its composition by 92% Copper, 8% Tin and a residual Phosphor, it is a reddish metal. In the musical strings they produce velvety, low and warm sound, with greater durability.


Giannini began building guitars in Brazil in 1900 and is currently one of the largest guitar manufacturers in the world. Production of instrument strings started in 1940 and Giannini is now one of the largest string manufacturers, producing millions of sets of strings each year. Its strings have been developed and designed with precision technology ensuring high fidelity sound, precision tuning and long lasting durability. Manufactured in Brazil utilizing the most modern equipment, Giannini was the first string manufacturer in Latin America to be certified ISO9001 for quality management and construction. 

Giannini strings are available for acoustic and electric guitars, classical guitars, acoustic and electric basses, Violins and Violas, Mandolins, Cavaquinhos and 10 string Brazilian Violas. All sets are sealed in an Anti-Corrosive protective enclosure to ensure maximum performance. Its products pass through a strict process of quality control and leave the factory fully imbued with the reliability, craftsmanship, and ultimate care that has been the hallmark of the Giannini name since 1900. Giannini, the perfect match for all of your stringed instruments.


All Giannini strings are produced in Brazil, at their factory in Salto, in São Paulo.

ISO 9001 Quality Seal

The entire line of Giannini strings has the approval of the ISO 9001quality seal. But what is the ISO 9001 seal?

ISO 9001 is a series of norms and rules that seek to guarantee the final quality of your strings. These procedures range from the choice of the raw material and its suppliers, going through the entire production process of the strings, training of the labor involved in the production, its distribution, until the product reaches the dealers and the consumer. These processes and all those involved in it undergo audits every year, to verify that they are being followed according to the established standard, so that the seal is renewed.

Since 2007, Giannini has been awarded the ISO 9001 seal in its strings line, which is renewed annually, proving the quality of each string that you use in your instrument.