Hose Clamp Size Chart

What it is

SAE J1508 covers hose clamps used on vehicle and equipment hoses, including worm-drive, spring and T-bolt types. Worm-drive clamps are sold by an SAE size number. The number is a size name, not a diameter. Each size covers a range from its smallest to largest diameter. Exact ranges vary slightly by maker and band width, so check the package.

How to use it

Measure the outside diameter of the hose when it is installed on the fitting, not the hose ID and not the fitting OD. Pick a size whose range puts that diameter near the middle, so the clamp has room to tighten and to be retightened later.

Approximate worm-drive clamp ranges

Minimum diameters in particular vary by maker. The package range governs.

Key points

• Stainless band and screw clamps resist corrosion. Plated carbon steel screws rust in wet areas.
• Lined clamps (with a smooth inner band) protect soft silicone hose from being cut by the band slots.
• Charge-air and large coolant hoses on heavy trucks often use T-bolt or constant-tension clamps that keep pressure as the hose heats and cools.
• Tighten to the clamp maker's installation torque. Overtightening cuts the hose and strips the screw.
• Place the clamp past the fitting's bead, not on top of it.

Common mistakes

• Choosing the size from the hose ID.
• Using a clamp at the very end of its range, so it cannot be retightened.
• Overtightening silicone hose with an unlined clamp.

Governing standards: SAE J1508 (hose clamp specifications). Clamp manufacturer's size ranges and installation data govern.

Reference only. Verify against the current governing code or standard, the manufacturer's data and the project documents before use. Apps for Distributors disclaims liability arising from reliance on this reference.