Koh-i-noor 12 Sketching Flat Graphite Pencils. 2B. 1538

12 Graphite pencils: 6B. Graphite base products are a very traditional product of KOH-I-NOOR HARDTMUTH a.s., with history dating back to 1790. The combination of basic raw materials ? low-sintering soft clays and pure, modified ground graphite powder and its complex homogenisation creates a mixture for the production of 20 gradations of graphite leads, with the scope of 8B to 10H. Soft gradations are marked with the letter B taken from the word ?Black? and hard gradations are marked with the letter H, which comes from the word ?Hard?. There are two gradations between these two groups marked HB (HardBlack) and F (Fine). The method of production is the same for all lengths, diameters and shapes of graphite leads. Under moist conditions, the pre-prepared mixture for the required gradation is formed into leads by stretching, which are then dried. The dried leads are burnt at a temperature of almost 1000°C and then impregnated with a mixture of fat, oil and paraffin. Special mo