Hose Clamp Guide: Worm Gear vs T-Bolt vs Spring Clamps and How to Size Them

November 9, 2026 · RPS Distributors

Hose clamps hold coolant, fuel, air intake and vacuum hoses in place. When a clamp loosens or fails, the result can be an overheated engine, a fuel leak or a loss of power. Winter makes it worse, because rubber shrinks in the cold and clamps can lose tension.

The main types

Worm gear clamps — the most common type. A screw tightens a band around the hose. Good for most coolant, fuel and general hoses.
T-bolt clamps — stronger and more even clamping force. Used on large turbo, charge-air and heavy-duty coolant hoses.
Spring (constant tension) clamps — automatically adjust as hoses expand and shrink with temperature. Often used by vehicle makers on coolant hoses.

How to size a hose clamp

Measure the outside diameter of the hose after it is installed on the fitting. Choose a clamp whose range includes that size, ideally with the hose diameter near the middle of the clamp's range. Clamp numbers such as #10 or #12 refer to a size range — check the range printed on the package.

Installation tips

Place the clamp just behind the bead or flare on the fitting.
Do not overtighten — it can cut into the hose.
Use stainless steel clamps in areas exposed to road salt.
Re-check coolant hose clamps after the engine has gone through a few heat cycles.