TQC sheen – Hardness / Scratch Resistance Testers – Pencils For Hardness Test According Wolff Wilborn

Koh-I-Noor 1500 set of 20 pencils in an aluminum case to use with the Wolff Wilborn Hardness Test. Pencils ranging from 8b to 10H (8B, 7B, 6B, 5B, 4B, 3B, 2B, B, HB, F, H, 2H, 3H, 4H, 5H, 6H, 7H, 8H, 9H, 10H)

The ISO 15184 standard refers to this Koh-i-noor 1500 pencil set.