Will these saws fit my existing drill press or hand drill?

Standard arbor design works with most drill chucks. Test-fit one saw to your drill before committing the full set to a project—different drill models have varying chuck tolerances.

Do I need cutting fluid when drilling through aluminum or steel?

Cutting fluid extends saw life and reduces heat buildup, especially on steel. It's not required but makes the job cleaner and the teeth last longer.

Can I use these on plastic ducting and fiberglass panels?

Yes. Bi-metal saws handle plastic and fiberglass without shattering or melting, as long as you keep drill speed moderate and let the saw do the work—don't force it.