Zero clips manufactures exhaust clamps- U Bolt type with plate and a M8 thread. These clamps are available in zinc as per your required specification

Exhaust clamps are mechanical devices used to secure and seal the joints between different sections of a vehicle's exhaust system. They come in various designs, such as U-bolt, band, and V-band clamps, each suited for specific applications and pipe diameters. Exhaust clamps ensure a tight fit to prevent exhaust leaks, which can affect vehicle performance and emissions. They are typically made from durable materials like stainless steel to withstand high temperatures and corrosion