Greyhound Auto Retail supplies hose clamps and clamps in a range of diameters for coolant, fuel, air, vacuum and general workshop hose applications.

Worm drive clamps are the standard answer for most jobs, and sizing is straightforward: pick a clamp whose range puts the hose comfortably in the middle rather than at either extreme, since a clamp wound out to its limit grips unevenly and one wound down too far bites into the hose.

A few practical points. Position the clamp behind the barb or bead on the fitting so it cannot slide off, tighten firmly but not so hard that the band cuts into the rubber, and re-check coolant and boost hose clamps after the first heat cycle because hoses take a set and often need a small nip up. Replace rather than reuse rusted clamps.

For fuel lines, see Fuel Hose: Neptune reinforced fuel hose for petrol and diesel in 3.2, 5, 6, 8, 10 and 12 mm, sold in cut lengths from 0.25 m or as full 30 m rolls, each with its matching clamp.