Reference number
ISO 9177-2:1989
ISO 9177-2:1989
© ISO 2024
ISO 9177-2:1989
Mechanical pencils — Part 2: Black leads — Classification and dimensions
Edition 1
1989-03
1989-03
Retirada
Resumen
Two types are available, black leads in which the binding agent is an organic polymer (designated by the letter "P"), and black leads in which the binding agent is clay (designated by the letter "C"). Classification is made according to the degree of hardness. Part 1 deals with the classification, dimensions, performance requirements and testing.
Ciclo de vida
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Ahora
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Revisada por
PublicadoISO 9177-2:2022