They are attached to the supporting structure either with a machine screw and nut. In blind applications, they are attached with a machine screw and a rivnut or plate nut.
Earls Plumbing Hose Clamp 171004ERL;
Earl's 171004ERL Hose Clamp
Earls 750006ERL Vapor Guard Screw Type 3/8 Hose Clamp 5/Pack
Hose Clamp Earls Plumbing 900506ERL
Earls Performance 750010ERL Hose Clamp
Earls Plumbing Hose Clamp 750005ERL;