PSA-backed (pressure sensitive adhesive) lapping film is extremely easy to use

Soak the stone for 1-2 minutes and splash water on the stone's surface to prevent drying

We can say for sure that Gritomatic uses harder bonding for 120 and 220 grit

This is not a defect

Remove the assembly screw

boride golden star stone for edge pro Grit:800 PSA-backed (pressure sensitive adhesive) lappingBoride Sharpening Stones are used for sharpening knives on Hapstone Pro sharpeners. Boride offers a wide range of stones with different performance values and different rates of wear. Boride stones are made of aluminum oxide, with the exception of CS HD series stones, which are made of silicon carbide. All Boride stones are 6 mm thick and are mounted on high quality aluminum blanks. Stones that are 6 mm thick offer a longer life cycle than stock Edge