Can I use one plier for both internal and external rings?

No. Internal pliers spread apart to fit inside rings; external pliers close inward to grip outer rings. Using the wrong one will slip off and damage the ring or your knuckles. This set includes both so you're covered for any circlip job.

Are these pliers forged or stamped?

Construction method isn't specified in the product data. Before ordering, confirm the material grade and manufacturing process if durability under high torque is critical for your application.

Will these fit inside tight transmission bellhousings?

At 16 inches, they're long enough to reach deep into most engine bays and gearbox cavities. If you're working in an extremely confined space, test-fit the plier tips in your specific assembly before committing to this set.