This Standard specifies chalks made of calcined plaster and calcium carbonate to be used on a blackboard (hereafter referred to as "chalks").
In addition, chalks include those surface treated in order to prevent hands from getting dirty and those contain recycled materials.
JIS S 6009:2013 Referenced Document
JIS B 7507 Geometrical product specifications (GPS) -- Dimensional measuring equipment -- Vernier, dial and digital callipers*， 2022-05-20 Update
JIS K 0050 General rules for chemical analysis*， 2019-02-20 Update
JIS K 0121 General rules for atomic absorption spectrometry
JIS K 8180 Hydrochloric acid (Reagent)*， 2021-02-22 Update