noun
secondary material; subsidiary material
Refers to materials that support or supplement primary materials in manufacturing, construction, or other processes. Often used in technical or business contexts.
この製品の副資材には再生プラスチックを使っています。
We use recycled plastic as a secondary material for this product.
副資材のコスト削減が全体の利益に大きく影響する。
Reducing the cost of subsidiary materials significantly affects overall profits.
原材料 is a broader term for raw materials, whereas 副資材 specifically denotes materials that play a supporting role in production.
Compound of 副 (ふく, 'secondary, auxiliary') and 資材 (しざい, 'materials, resources'). The term is a modern technical coinage.