How hard is a acorn or oak nut?

Acorns and oak nuts are both very hard. The hardness of an acorn or oak nut is measured on the Janka hardness scale, which measures the resistance of wood to denting and wear. The Janka hardness scale ranges from 0 to 4,000, with higher numbers indicating harder wood. Acorns and oak nuts typically have a Janka hardness of around 2,000, which is comparable to the hardness of red oak and white oak. This means that acorns and oak nuts are very hard and can be difficult to crack or break.