General term for materials used in construction, manufacturing, or other projects. Often appears in compound nouns like 建築用材 (building materials).
この工場では建築用材を生産している。
This factory produces construction materials.
Specifically refers to wood used as a material, especially in construction or woodworking.
良質の用材を確保するのが難しい。
It is difficult to secure high-quality lumber.
Compound of 用 (use, purpose) and 材 (material, lumber). The reading ようざい is the standard on'yomi combination.