Tri Clamp – Hinged with 1 bolt and 1 wingnut or 2 bolts with 2 wingnuts. SS AISI 316L DIN1.4404 is most used because most of the machine parts are made in this material. SS AISI 304 DIN 1.4301 is also available because the clamps are on the outside of the tube and have less contact with cleaning fluids or product which flow through the tubing so have a lower price. Clamps are sold with 1 or 2 wingnuts. Option for Hexagon Nuts are sold seperately. Optional also are nuts fitted with a tube which you can put a padlock through locking the access to the nut.