FIX-A-TAP hose clamps feature slotted and hexagonal heads so that they can easily be tightened with a screwdriver or spanner. These stainless-steel hose clamps are designed to resist rust and corrosion. Size #1 will suit hoses measured 27-40mm. Stainless steel hose clamps. A wide range of clamp sizes are available, from 9mm to 70mm, to fit any hose.