A machine designed or adapted principally for testing metals goes under 902410. A machine capable of testing multiple material types but not principally designed for metals would typically fall under 902480 as a machine for testing other mechanical properties. The principal design and the manufacturer's specifications are the primary classification guides; a binding ruling from CBP is advisable for multipurpose systems.

Yes, provided they are identifiable as parts or accessories for material-testing machines of this heading. Load cells, grips, extensometers, and similar components designed for use with machines of 9024 classify under 902490. However, a load cell that is a general-purpose transducer not specifically designed for material-testing machines may be classified elsewhere, so the article's design specificity matters.