Brinell Hardness
Standardised test method for determining wood hardness.
Brinell hardness is the most common method in Europe for measuring wood hardness. A steel ball of 10 mm diameter is pressed against the wood surface with a defined force and the impression area is measured. The value is given in N/mm². Typical values for stair timbers: oak approx. 34, beech approx. 34, ash approx. 38, maple approx. 27, walnut approx. 27 N/mm². The higher the value, the more resistant the wood is to scratches and dents — a decisive factor when selecting stair treads.