The hardest solid wood floor is typically American Cherry. American Cherry has a Janka hardness rating of 1,290, which is significantly higher than other popular wood species like oak (1,510) and maple (1,450). This rating indicates the wood's resistance to dents and scratches, making it an excellent choice for high-traffic areas.

The Janka hardness test measures the force required to embed a .444-inch steel ball halfway into the wood. Higher numbers indicate harder wood. American Cherry's high Janka rating is due to its dense and tight grain structure, which provides excellent durability. Additionally, Cherry wood is known for its rich color and grain pattern, making it a popular choice for both residential and commercial flooring applications.