Do these clamps come with bolts and hardware?

The set includes the clamp bands. Mounting hardware (bolts, nuts, washers) is not included — source fasteners separately to match your installation diameter and thread pitch.

Can I use these on a custom exhaust build without welding?

Yes. Lap joint clamps tighten around overlapping tube ends to create a secure, non-welded connection. Tighten evenly in a cross pattern and check alignment before final torque.

Will stainless steel hold up better than a regular steel clamp?

Stainless resists rust and heat discoloration, so it'll stay cleaner and last longer in exhaust heat. You won't see the orange bloom that mild steel clamps develop over time.