(in Russian – ГОСТ 4404-78 Графит для производства карандашных стержней. Технические условия).

This standard applies to crystalline natural graphite obtained by beneficiation of graphite ores of the Zavalyevskoe and Taiginskoye deposits and intended for the manufacture of pencil rods.

Depending on the application, graphite should be produced in the following grades:

Graphite GK-0 (ГК-0) – for pencils of the drawing group

Ash content, %, not more than = 1.0
Moisture content, %, not more than = 0.5
The release of volatile substances, including from flotation reagents, %, not more than = 0.5
The residue on the sieve No. 0063, %, not more than = not standardized
The residue on the sieve No. 0045, %, not more than = 0.5
Bulk density, kg / dm3 = 150 – 200
The particles less than 40 microns in size, %, not less than = 90
Arsenic content (As), %, not more than = 0.0025

Graphite GK-1 (ГК-1) – for pencils of the drawing and stationery groups

Ash content, %, not more than = 1.0
Moisture content, %, not more than = 0.5
The release of volatile substances, including from flotation reagents, %, not more than = 0.5
The residue on the sieve No. 0063, %, not more than = 0.5
The residue on the sieve No. 0045, %, not more than = not standardized
Bulk density, kg / dm3 = not standardized
The particles less than 40 microns in size, %, not less than = not standardized
Arsenic content (As), %, not more than = 0.0025

Graphite GK-2 (ГК-2) – for pencils of the stationery, school and copying groups

Ash content, %, not more than = 3.0
Moisture content, %, not more than = 1.0
The release of volatile substances, including from flotation reagents, %, not more than = 1.0
The residue on the sieve No. 0063, %, not more than = 0.5
The residue on the sieve No. 0045, %, not more than = not standardized
Bulk density, kg / dm3 = not standardized
The particles less than 40 microns in size, %, not less than = not standardized
Arsenic content (As), %, not more than = 0.0025

Graphite GK-3 (ГК-3) – for pencils for stationery, school and copying groups

Ash content, %, not more than = 5.0
Moisture content, %, not more than = 2.0
The release of volatile substances, including from flotation reagents, %, not more than = 1.0
The residue on the sieve No. 0063, %, not more than = 1.0
The residue on the sieve No. 0045, %, not more than = not standardized
Bulk density, kg / dm3 = not standardized
The particles less than 40 microns in size, %, not less than = not standardized
Arsenic content (As), %, not more than = 0.0025